6.1. Multiple assignment¶
As you may have discovered, it is legal to make more than one assignment to thesame variable. A new assignment makes an existing variable refer to a new value(and stop referring to the old value).
bruce = 5print bruce,bruce = 7print bruce
The output of this program is 5 7, because the first time bruce isprinted, his value is 5, and the second time, his value is 7. The comma at theend of the first print statement suppresses the newline after the output,which is why both outputs appear on the same line.
Here is what multiple assignment looks like in a state diagram:
With multiple assignment it is especially important to distinguish between anassignment operation and a statement of equality. Because Python uses the equalsign (=) for assignment, it is tempting to interpret a statement likea = b as a statement of equality. It is not!
First, equality is symmetric and assignment is not. For example, inmathematics, if a = 7 then 7 = a. But in Python, the statement a = 7is legal and 7 = a is not.
Furthermore, in mathematics, a statement of equality is always true. If a = bnow, then a will always equal b. In Python, an assignment statement can maketwo variables equal, but they don’t have to stay that way:
a = 5b = a # a and b are now equala = 3 # a and b are no longer equal
The third line changes the value of a but does not change the value ofb, so they are no longer equal. (In some programming languages, a differentsymbol is used for assignment, such as <- or :=, to avoid confusion.)
6.2. Updating variables¶
One of the most common forms of multiple assignment is an update, where the newvalue of the variable depends on the old.
x = x + 1
This means get the current value of x, add one, and then update x with the newvalue.
If you try to update a variable that doesn’t exist, you get an error, becausePython evaluates the expression on the right side of the assignment operatorbefore it assigns the resulting value to the name on the left:
>>> x = x + 1Traceback (most recent call last): File "", line 1, inNameError: name 'x' is not defined
Before you can update a variable, you have to initialize it, usually with asimple assignment:
>>> x = 0>>> x = x + 1>>>
Updating a variable by adding 1 is called an increment; subtracting 1 iscalled a decrement.
6.3. The while statement¶
Computers are often used to automate repetitive tasks. Repeating identical orsimilar tasks without making errors is something that computers do well andpeople do poorly.
Repeated execution of a set of statements is called iteration. Becauseiteration is so common, Python provides several language features to make iteasier. The first feature we are going to look at is the while statement.
Here is a function called countdown that demonstrates the use of thewhile statement:
def countdown(n): while n > 0: print n n = n-1 print "Blastoff!"
You can almost read the while statement as if it were English. It means,While n is greater than 0, continue displaying the value of n and thenreducing the value of n by 1. When you get to 0, display the wordBlastoff!
More formally, here is the flow of execution for a while statement:
- Evaluate the condition, yielding False or True.
- If the condition is false, exit the while statement and continueexecution at the next statement.
- If the condition is true, execute each of the statements in the body andthen go back to step 1.
The body consists of all of the statements below the header with the sameindentation.
This type of flow is called a loop because the third step loops back aroundto the top. Notice that if the condition is false the first time through theloop, the statements inside the loop are never executed.
The body of the loop should change the value of one or more variables so thateventually the condition becomes false and the loop terminates. Otherwise theloop will repeat forever, which is called an infinite loop. An endlesssource of amusement for computer scientists is the observation that thedirections on shampoo, Lather, rinse, repeat, are an infinite loop.
In the case of countdown, we can prove that the loop terminates because weknow that the value of n is finite, and we can see that the value of ngets smaller each time through the loop, so eventually we have to get to 0. Inother cases, it is not so easy to tell. Look at the following function,defined for all positive integers n:
def sequence(n): while n != 1: print n, if n % 2 == 0: # n is even n = n / 2 else: # n is odd n = n * 3 + 1
The condition for this loop is n != 1, so the loop will continue untiln is 1, which will make the condition false.
Each time through the loop, the program outputs the value of n and thenchecks whether it is even or odd. If it is even, the value of n is dividedby 2. If it is odd, the value is replaced by n * 3 + 1. For example, ifthe starting value (the argument passed to sequence) is 3, the resultingsequence is 3, 10, 5, 16, 8, 4, 2, 1.
Since n sometimes increases and sometimes decreases, there is no obviousproof that n will ever reach 1, or that the program terminates. For someparticular values of n, we can prove termination. For example, if thestarting value is a power of two, then the value of n will be even eachtime through the loop until it reaches 1. The previous example ends with such asequence, starting with 16.
Particular values aside, the interesting question is whether we can prove thatthis program terminates for all values of n. So far, no one has been ableto prove it or disprove it!
6.4. Tracing a program¶
To write effective computer programs a programmer needs to develop the abilityto trace the execution of a computer program. Tracing involves becoming thecomputer and following the flow of execution through a sample program run,recording the state of all variables and any output the program generates aftereach instruction is executed.
To understand this process, let’s trace the call to sequence(3) from theprevious section. At the start of the trace, we have a local variable, n(the parameter), with an initial value of 3. Since 3 is not equal to 1, thewhile loop body is executed. 3 is printed and 3 % 2 == 0 is evaluated.Since it evaluates to False, the else branch is executed and3 * 3 + 1 is evaluated and assigned to n.
To keep track of all this as you hand trace a program, make a column heading ona piece of paper for each variable created as the program runs and another onefor output. Our trace so far would look something like this:
n output-- ------3 310
Since 10 != 1 evaluates to True, the loop body is again executed,and 10 is printed. 10 % 2 == 0 is true, so the if branch isexecuted and n becomes 5. By the end of the trace we have:
n output-- ------3 310 105 516 168 84 42 21
Tracing can be a bit tedious and error prone (that’s why we get computers to dothis stuff in the first place!), but it is an essential skill for a programmerto have. From this trace we can learn a lot about the way our code works. Wecan observe that as soon as n becomes a power of 2, for example, the programwill require log2(n) executions of the loop body to complete. We canalso see that the final 1 will not be printed as output.
6.5. Counting digits¶
The following function counts the number of decimal digits in a positiveinteger expressed in decimal format:
def num_digits(n): count = 0 while n: count = count + 1 n = n / 10 return count
A call to num_digits(710) will return 3. Trace the execution of thisfunction call to convince yourself that it works.
This function demonstrates another pattern of computation called a counter.The variable count is initialized to 0 and then incremented each time theloop body is executed. When the loop exits, count contains the result –the total number of times the loop body was executed, which is the same as thenumber of digits.
If we wanted to only count digits that are either 0 or 5, adding a conditionalbefore incrementing the counter will do the trick:
def num_zero_and_five_digits(n): count = 0 while n: digit = n % 10 if digit == 0 or digit == 5: count = count + 1 n = n / 10 return count
Confirm that num_zero_and_five_digits(1055030250) returns 7.
6.6. Abbreviated assignment¶
Incrementing a variable is so common that Python provides an abbreviated syntaxfor it:
>>> count = 0>>> count += 1>>> count1>>> count += 1>>> count2>>>
count += 1 is an abreviation for count = count + 1 . The incrementvalue does not have to be 1:
>>> n = 2>>> n += 5>>> n7>>>
There are also abbreviations for -=, *=, /=, and %=:
>>> n = 2>>> n *= 5>>> n10>>> n -= 4>>> n6>>> n /= 2>>> n3>>> n %= 2>>> n1
One of the things loops are good for is generating tabular data. Beforecomputers were readily available, people had to calculate logarithms, sines andcosines, and other mathematical functions by hand. To make that easier,mathematics books contained long tables listing the values of these functions.Creating the tables was slow and boring, and they tended to be full of errors.
When computers appeared on the scene, one of the initial reactions was, This isgreat! We can use the computers to generate the tables, so there will be noerrors. That turned out to be true (mostly) but shortsighted. Soon thereafter,computers and calculators were so pervasive that the tables became obsolete.
Well, almost. For some operations, computers use tables of values to get anapproximate answer and then perform computations to improve the approximation.In some cases, there have been errors in the underlying tables, most famouslyin the table the Intel Pentium used to perform floating-point division.
Although a log table is not as useful as it once was, it still makes a goodexample of iteration. The following program outputs a sequence of values in theleft column and 2 raised to the power of that value in the right column:
x = 1while x < 13: print x, '\t', 2**x x += 1
The string '\t' represents a tab character. The backslash character in'\t' indicates the beginning of an escape sequence. Escape sequencesare used to represent invisible characters like tabs and newlines. The sequence\n represents a newline.
An escape sequence can appear anywhere in a string; in this example, the tabescape sequence is the only thing in the string. How do you think you representa backslash in a string?
As characters and strings are displayed on the screen, an invisible markercalled the cursor keeps track of where the next character will go. After aprint statement, the cursor normally goes to the beginning of the nextline.
The tab character shifts the cursor to the right until it reaches one of thetab stops. Tabs are useful for making columns of text line up, as in the outputof the previous program:
1 22 43 84 165 326 647 1288 2569 51210 102411 204812 4096
Because of the tab characters between the columns, the position of the secondcolumn does not depend on the number of digits in the first column.
6.8. Two-dimensional tables¶
A two-dimensional table is a table where you read the value at the intersectionof a row and a column. A multiplication table is a good example. Let’s say youwant to print a multiplication table for the values from 1 to 6.
A good way to start is to write a loop that prints the multiples of 2, all onone line:
i = 1while i <= 6: print 2 * i, ' ', i += 1print
The first line initializes a variable named i, which acts as a counter orloop variable. As the loop executes, the value of i increases from 1 to6. When i is 7, the loop terminates. Each time through the loop, itdisplays the value of 2 * i, followed by three spaces.
Again, the comma in the print statement suppresses the newline. After theloop completes, the second print statement starts a new line.
The output of the program is:
2 4 6 8 10 12
So far, so good. The next step is to encapsulate and generalize.
6.9. Encapsulation and generalization¶
Encapsulation is the process of wrapping a piece of code in a function,allowing you to take advantage of all the things functions are good for. Youhave already seen two examples of encapsulation: print_parity in chapter 4;and is_divisible in chapter 5.
Generalization means taking something specific, such as printing the multiplesof 2, and making it more general, such as printing the multiples of anyinteger.
This function encapsulates the previous loop and generalizes it to printmultiples of n:
def print_multiples(n): i = 1 while i <= 6: print n * i, '\t', i += 1 print
To encapsulate, all we had to do was add the first line, which declares thename of the function and the parameter list. To generalize, all we had to dowas replace the value 2 with the parameter n.
If we call this function with the argument 2, we get the same output as before.With the argument 3, the output is:
3 6 9 12 15 18
With the argument 4, the output is:
4 8 12 16 20 24
By now you can probably guess how to print a multiplication table — bycalling print_multiples repeatedly with different arguments. In fact, wecan use another loop:
i = 1while i <= 6: print_multiples(i) i += 1
Notice how similar this loop is to the one inside print_multiples. All wedid was replace the print statement with a function call.
The output of this program is a multiplication table:
1 2 3 4 5 62 4 6 8 10 123 6 9 12 15 184 8 12 16 20 245 10 15 20 25 306 12 18 24 30 36
6.10. More encapsulation¶
To demonstrate encapsulation again, let’s take the code from the last sectionand wrap it up in a function:
def print_mult_table(): i = 1 while i <= 6: print_multiples(i) i += 1
This process is a common development plan. We develop code by writing linesof code outside any function, or typing them in to the interpreter. When we getthe code working, we extract it and wrap it up in a function.
This development plan is particularly useful if you don’t know how to dividethe program into functions when you start writing. This approach lets youdesign as you go along.
6.11. Local variables¶
You might be wondering how we can use the same variable, i, in bothprint_multiples and print_mult_table. Doesn’t it cause problems whenone of the functions changes the value of the variable?
The answer is no, because the i in print_multiples and the i inprint_mult_table are not the same variable.
Variables created inside a function definition are local; you can’t access alocal variable from outside its home function. That means you are free to havemultiple variables with the same name as long as they are not in the samefunction.
The stack diagram for this program shows that the two variables named i arenot the same variable. They can refer to different values, and changing onedoes not affect the other.
The value of i in print_mult_table goes from 1 to 6. In the diagram ithappens to be 3. The next time through the loop it will be 4. Each time throughthe loop, print_mult_table calls print_multiples with the current valueof i as an argument. That value gets assigned to the parameter n.
Inside print_multiples, the value of i goes from 1 to 6. In thediagram, it happens to be 2. Changing this variable has no effect on the valueof i in print_mult_table.
It is common and perfectly legal to have different local variables with thesame name. In particular, names like i and j are used frequently asloop variables. If you avoid using them in one function just because you usedthem somewhere else, you will probably make the program harder to read.
6.12. More generalization¶
As another example of generalization, imagine you wanted a program that wouldprint a multiplication table of any size, not just the six-by-six table. Youcould add a parameter to print_mult_table:
def print_mult_table(high): i = 1 while i <= high: print_multiples(i) i += 1
We replaced the value 6 with the parameter high. If we callprint_mult_table with the argument 7, it displays:
1 2 3 4 5 62 4 6 8 10 123 6 9 12 15 184 8 12 16 20 245 10 15 20 25 306 12 18 24 30 367 14 21 28 35 42
This is fine, except that we probably want the table to be square — with thesame number of rows and columns. To do that, we add another parameter toprint_multiples to specify how many columns the table should have.
Just to be annoying, we call this parameter high, demonstrating thatdifferent functions can have parameters with the same name (just like localvariables). Here’s the whole program:
def print_multiples(n, high): i = 1 while i <= high: print n*i, '\t', i += 1 printdef print_mult_table(high): i = 1 while i <= high: print_multiples(i, high) i += 1
Notice that when we added a new parameter, we had to change the first line ofthe function (the function heading), and we also had to change the place wherethe function is called in print_mult_table.
As expected, this program generates a square seven-by-seven table:
1 2 3 4 5 6 72 4 6 8 10 12 143 6 9 12 15 18 214 8 12 16 20 24 285 10 15 20 25 30 356 12 18 24 30 36 427 14 21 28 35 42 49
When you generalize a function appropriately, you often get a program withcapabilities you didn’t plan. For example, you might notice that, because ab =ba, all the entries in the table appear twice. You could save ink by printingonly half the table. To do that, you only have to change one line ofprint_mult_table. Change
and you get:
12 43 6 94 8 12 165 10 15 20 256 12 18 24 30 367 14 21 28 35 42 49
A few times now, we have mentioned all the things functions are good for. Bynow, you might be wondering what exactly those things are. Here are some ofthem:
- Giving a name to a sequence of statements makes your program easier to readand debug.
- Dividing a long program into functions allows you to separate parts of theprogram, debug them in isolation, and then compose them into a whole.
- Functions facilitate the use of iteration.
- Well-designed functions are often useful for many programs. Once you writeand debug one, you can reuse it.
6.14. Newton’s Method¶
Loops are often used in programs that compute numerical results by startingwith an approximate answer and iteratively improving it.
For example, one way of computing square roots is Newton’s method. Supposethat you want to know the square root of n. If you start with almost anyapproximation, you can compute a better approximation with the followingformula:
better = (approx + n/approx)/2
By repeatedly applying this formula until the better approximation is equal tothe previous one, we can write a function for computing the square root:
def sqrt(n): approx = n/2.0 better = (approx + n/approx)/2.0 while better != approx: approx = better better = (approx + n/approx)/2.0 return approx
Try calling this function with 25 as an argument to confirm that it returns 5.0.
Newton’s method is an example of an algorithm: it is a mechanical processfor solving a category of problems (in this case, computing square roots).
It is not easy to define an algorithm. It might help to start with somethingthat is not an algorithm. When you learned to multiply single-digit numbers,you probably memorized the multiplication table. In effect, you memorized 100specific solutions. That kind of knowledge is not algorithmic.
But if you were lazy, you probably cheated by learning a few tricks. Forexample, to find the product of n and 9, you can write n - 1 as the first digitand 10 - n as the second digit. This trick is a general solution formultiplying any single-digit number by 9. That’s an algorithm!
Similarly, the techniques you learned for addition with carrying, subtractionwith borrowing, and long division are all algorithms. One of thecharacteristics of algorithms is that they do not require any intelligence tocarry out. They are mechanical processes in which each step follows from thelast according to a simple set of rules.
In our opinion, it is embarrassing that humans spend so much time in schoollearning to execute algorithms that, quite literally, require no intelligence.
On the other hand, the process of designing algorithms is interesting,intellectually challenging, and a central part of what we call programming.
Some of the things that people do naturally, without difficulty or consciousthought, are the hardest to express algorithmically. Understanding naturallanguage is a good example. We all do it, but so far no one has been able toexplain how we do it, at least not in the form of an algorithm.
- A step-by-step process for solving a category of problems.
- The statements inside a loop.
- A variable used to count something, usually initialized to zero andincremented in the body of a loop.
- An invisible marker that keeps track of where the next character willbe printed.
- Decrease by 1.
- development plan
- A process for developing a program. In this chapter, we demonstrated astyle of development based on developing code to do simple, specificthings and then encapsulating and generalizing.
- To divide a large complex program into components (like functions) andisolate the components from each other (by using local variables, forexample).
- escape sequence
- An escape character, \, followed by one or more printable charactersused to designate a nonprintable character.
- To replace something unnecessarily specific (like a constant value)with something appropriately general (like a variable or parameter).Generalization makes code more versatile, more likely to be reused, andsometimes even easier to write.
- Both as a noun and as a verb, increment means to increase by 1.
- infinite loop
- A loop in which the terminating condition is never satisfied.
- initialization (of a variable)
- To initialize a variable is to give it an initial value, usually in thecontext of multiple assignment. Since in Python variables don’t existuntil they are assigned values, they are initialized when they arecreated. In other programming languages this is not the case, andvariables can be created without being initialized, in which case theyhave either default or garbage values.
- Repeated execution of a set of programming statements.
- A statement or group of statements that execute repeatedly until aterminating condition is satisfied.
- loop variable
- A variable used as part of the terminating condition of a loop.
- multiple assignment
- Making more than one assignment to the same variable during theexecution of a program.
- A special character that causes the cursor to move to the beginning ofthe next line.
- A special character that causes the cursor to move to the next tab stopon the current line.
- To follow the flow of execution of a program by hand, recording thechange of state of the variables and any output produced.
Write a single string that:
Add a print statement to the sqrt function defined in section 6.14 thatprints out better each time it is calculated. Call your modifiedfunction with 25 as an argument and record the results.
Trace the execution of the last version of print_mult_table and figureout how it works.
Write a function print_triangular_numbers(n) that prints out the firstn triangular numbers. A call to print_triangular_numbers(5) wouldproduce the following output:
1 12 33 64 105 15
(hint: use a web search to find out what a triangular number is.)
Open a file named ch06.py and add the following:
if __name__ == '__main__': import doctest doctest.testmod()
Write a function, is_prime, which takes a single integral argumentand returns True when the argument is a prime number and Falseotherwise. Add doctests to your function as you develop it.
What will num_digits(0) return? Modify it to return 1 for thiscase. Why does a call to num_digits(-24) result in an infinite loop(hint: -1/10 evaluates to -1)? Modify num_digits so that it workscorrectly with any integer value. Add the following to the ch06.pyfile you created in the previous exercise:
def num_digits(n): """ >>> num_digits(12345) 5 >>> num_digits(0) 1 >>> num_digits(-12345) 5 """
Add your function body to num_digits and confirm that it passes thedoctests.
Add the following to the ch06.py:
def num_even_digits(n): """ >>> num_even_digits(123456) 3 >>> num_even_digits(2468) 4 >>> num_even_digits(1357) 0 >>> num_even_digits(2) 1 >>> num_even_digits(20) 2 """
Write a body for num_even_digits so that it works as expected.
Add the following to ch06.py:
def print_digits(n): """ >>> print_digits(13789) 9 8 7 3 1 >>> print_digits(39874613) 3 1 6 4 7 8 9 3 >>> print_digits(213141) 1 4 1 3 1 2 """
Write a body for print_digits so that it passes the given doctests.
Write a function sum_of_squares_of_digits that computes the sumof the squares of the digits of an integer passed to it. For example,sum_of_squares_of_digits(987) should return 194, since9**2 + 8**2 + 7**2 == 81 + 64 + 49 == 194.
def sum_of_squares_of_digits(n): """ >>> sum_of_squares_of_digits(1) 1 >>> sum_of_squares_of_digits(9) 81 >>> sum_of_squares_of_digits(11) 2 >>> sum_of_squares_of_digits(121) 6 >>> sum_of_squares_of_digits(987) 194 """
Check your solution against the doctests above.(Video) I've read over 100 coding books. Here's what I learned
© Copyright 2010, Jeffrey Elkner, Allen B. Downey and Chris Meyers. Created using Sphinx 1.2.2.
If you plan to spend a couple hours each week studying and practicing, then you can expect to take several weeks to complete a Python crash course. If you plan to spend an hour or two each day, then you can expect to complete a Python crash course more quickly.Is Python 2 still worth learning? ›
Yes, learning Python is worth it in 2022 because some of the hottest fields in tech – including machine learning and artificial intelligence – rely heavily on programmers with Python skills.What is the fastest way to learn Python? ›
- Make It Stick. Tip #1: Code Everyday. Tip #2: Write It Out. ...
- Make It Collaborative. Tip #6: Surround Yourself With Others Who Are Learning. Tip #7: Teach. ...
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- Go Forth and Learn!
Luckily, there's no shortage of excellent books that can help you learn both the basic concepts of programming and the specifics of programming in Python.Is 2 months enough to learn Python? ›
In general, it takes around two to six months to learn the fundamentals of Python. But you can learn enough to write your first short program in a matter of minutes. Developing mastery of Python's vast array of libraries can take months or years.Can I learn Python in 4 days? ›
While you can start to write small scripts in Python after just a few days of study, you'll probably spend around four months gaining an essential ability in programming with Python. You'll have to spend years and build many projects to become a Python expert in even just one field.Is it better to learn Python 2 or Python 3? ›
While Python 2 had its heyday in the early 2000s, Python 3 is the best choice to learn in 2022. You might find some circumstances in which you need to use Python 2, but on the whole, Python 3 is the most popular language. Since Python 2 was sunsetted in 2020, Python 3 has dominated the programming world.How long does it take to learn Python 2? ›
If you're looking for a general answer, here it is: If you just want to learn the Python basics, it may only take a few weeks. However, if you're pursuing a data science career from the beginning, you can expect it to take four to twelve months to learn enough advanced Python to be job-ready.Which is easier Python 2 or 3? ›
Python 3 has an easier syntax compared to Python 2. A lot of libraries of Python 2 are not forward compatible. A lot of libraries are created in Python 3 to be strictly used with Python 3. Python 2 is no longer in use since 2020.How long should I learn Python a day? ›
If you study 2 to 3 hours a day, you will be able to learn python fairly quickly, even without a programming background. Python is a simple language that commonly used as a language to teach programming. At Boston University, freshman engineering and computer science students learn python as a first language.
- Google's Python Class. ...
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You should have a clear understanding of Python syntax, statements, variables & operators, control structures, functions & modules, OOP concepts, exception handling, and various other concepts before going out for a Python interview. There are numerous quality courses available over the web that can help you in this.What is the best age to learn Python? ›
Introduction to Python is geared toward kids 12 and older. Kids start by learning about coding fundamentals such as variables, loops, and if/then statements. From there, they progress to working with graphics and eventually to building games.Is learn Python in one day a good book? ›
On a positive note this book is better for a very first coding reader than other Python books I have reviewed. It is unlikely you will truly learn the language in one day but in a week you may have a decent handle on the very very basics. Good coding!Which Python is easiest to learn? ›
If you want the short answer, here it is: You should learn Python 3 because it's the version most relevant to today's data science projects. Plus, it's easy to learn, and there are few compatibility issues to worry about.How long will it take to learn Python if I study 2 3 hours everyday? ›
Another option is to devote yourself to Python for five months. This is for those of you who work full time. The plan must be to spend 2-3 hours a day on the computer. Learn one day, practice the same thing the other day.Is Python alone enough to get a job? ›
Yes, you can get a job by just knowing Python. Most of the machine learning programs are implemented using Python.What language does NASA use? ›
HAL/S (High-order Assembly Language/Shuttle) is a real-time aerospace programming language compiler and cross-compiler for avionics applications used by NASA and associated agencies (JPL, etc.).What is the hardest programming language? ›
Malbolge: One esoteric programming language is Malbolge.
The fact that it took at least two years to complete developing the first Malbolge code indicates that it is by far the toughest programming language to learn.
Java and Python are two of the most popular programming languages. Of the two, Java is the faster language, but Python is simpler and easier to learn. Each is well-established, platform-independent, and part of a large, supportive community.
Python 2 Risks In 2022
Python 2 applications will become less reliable and more vulnerable as bugs, security issues and CVEs continue to crop up, even 2 years after it was sunsetted. Popular packages have already sunset Python 2 support for their projects.
You might see Python 2 code in companies that don't see the upgrade to Python 3 as worth the effort. You may also run into the rare Python 2 library, and if it's necessary for your project and there are no alternatives, you may have no other choice than to write Python 2 code.Is there a big difference between Python 2 and 3? ›
Python 3 is more in-demand and includes a typing system. Python 2 is outdated and uses an older syntax for the print function. While Python 2 is still in use for configuration management in DevOps, Python 3 is the current standard. Python (the code, not the snake) is a popular coding language to learn for beginners.Do I need to learn Python 2 before 3? ›
Do I need to learn Python 2 before Python 3? Python 3 is the most recent version, and you don't need Python 2 experience to learn it. It makes sense to learn Python 3 first if you're just learning this programming language. The last version of Python 2 came out in 2020.Can I learn python in a month without any programming experience? ›
Yes, it's very possible to learn Python on your own and you can learn Python without any programming experience. There are a wide variety of learning resources available online free on the web to help you learn Python for everything from game development to robotics and artificial intelligence.Is it too late to learn Python? ›
of course not - it is never too late to learn a new skill. I started learning Python in 2010 - when I was 44. It's never too late to learn something!Is Python harder than C++? ›
Is C++ Harder Than Python? Yes, C++ is harder to learn and work with than Python . The biggest difference is that C++ has a more complex syntax to work with and involves more memory management than Python, which is both simple to learn and use. Python is considered a better beginner programming language.Is Python harder than C ++? ›
Python is an easier-to-use language: there are many jobs, and the language is growing. C++ is a harder-to-use language, but it's also more efficient — and while there aren't as many jobs, the salaries can be higher. Beginners are more likely to have success learning Python, at least at first.Is Python tougher than C++? ›
Python is easy to learn and easy to put in practice when compared to C++ which becomes harder as we advance through its features. Another advantage of Python is its libraries that allow us to write any functionality especially data analysis and machine learning. So popularity-wise Python scores over C++.Can I learn Python in 3 hours? ›
Learn Python in 3 hours is a fast-paced, action-packed course that maximizes your time; it's designed from the ground up to bring you from zero to hero in the shortest time. The course is based on many years of Python development experience in both large enterprises and nimble startups.
If you have a full-time job or you are a student, you can finish it in 5 months. After coming back from your work/school, spend 2–3 hours to learn python. Your goal will be to learn one day and practice the next day.Is Python worth learning 2022? ›
As per the above discussion, Python is worth learning in 2022 as there are more job opportunities for python developers and it has been considered as the most demanding future language in the Tech world.Can a non IT person learn Python? ›
Learning Python as a programmer, engineer or even a hobbyist has many benefits and brighter career opportunities are just a by-product of it. This is a super simple and very easy to follow the course to teach you python programming assuming that you've never done any kind of coding before.Can I learn Python at 45 and get a job? ›
For sure yes , if you have the desired skills and knowledge . No one will ever care about the age , there are plenty of jobs available in the field of python . Beside this you can also go for freelancing as an option.What is the salary if we learn Python? ›
The average salary of entry-level Python developer salary in India is ₹427,293. The average salary of a mid-level Python developer salary in India is ₹909,818. The average salary of an experienced Python developer salary in India is ₹1,150,000.Can I earn money as a beginner in Python? ›
Yes, I am not joking, this is absolutely real, anyone even a beginner can money with Python or any other technology/programming language. We are not lying, today, we are going to tell you the top 10 real and 100% working methods using which anyone from anywhere can make money.Is 40 too old to learn to code? ›
Let's get this out of the way: no, you are not too old to program. There isn't an age limit on learning to code, and there never was. But all too often, insecurity and uncertainty compel older adults to put a ceiling on their achievement potential.Is 50 too old to learn Python? ›
And once they reach their twenties, they are coding masterminds, knowing all the nooks and crannies of a given language. Well, that might be the case in a Netflix series. But the reality is different. The truth is that it's never too late to learn to code.What should a Python beginner know? ›
- Expertise In Core Python. Before jumping into a framework or a development environment, it is crucial to first master the core concepts of any programming language. ...
- Python Frameworks. ...
- Python Libraries. ...
- Front-End Technologies Knowledge. ...
- Machine Learning and AI. ...
- Deep Learning. ...
- Familiarity with ORM Libraries. ...
- Version Control.
It takes about 65 hours to complete all the courses in the Learn Programming with Python track. If you can spare three hours a day, you will complete the entire track in 22 days. Thus, you can finish it up in a month.
- Python Crash Course: A Hands-On, Project-Based Introduction to Programming by Eric Matthes. ...
- Automate the Boring Stuff With Python: Practical Programming for Total Beginners by Al Sweigart. ...
- Fluent Python: Clear, Concise, and Effective Programming by Luciano Ramalho.
Indentions. While indenting is usually just an annoying practice that programmers either live and die by or casually ignore, theres no getting around it with Python. Indentation is built directly into Pythons programming language, so youll have to learn quickly if you want to build anything!Is Python crash course enough to learn Python? ›
The short answer is no; the material in Python Crash Course is necessary for getting hired, but it's not sufficient. People aren't going to hire you for learning basic Python syntax; people might hire you if you can use what you've learned to solve the problems they care about.Is crash course on Python worth it? ›
The Crash Course on Python provides a practical application of how the concepts taught would be used in an IT job. I found the course to be more basic (in a good way) in its examples of programming and in its assignment prompts. This was great for a relative beginner in using Python.Is Python crash course a good book for beginners? ›
You don't need any programming experience to start learning with Python Crash Course. The book introduces you to the Python programming language and to object-oriented programming in general. Each coding concept is explained on a very detailed level. Perfect for complete beginners.How long does it take to learn Python full? ›
If you just want to learn the Python basics, it may only take a few weeks. However, if you're pursuing a data science career from the beginning, you can expect it to take four to twelve months to learn enough advanced Python to be job-ready.What is the best age to start learning Python? ›
Introduction to Python is geared toward kids 12 and older. Kids start by learning about coding fundamentals such as variables, loops, and if/then statements. From there, they progress to working with graphics and eventually to building games.Which version of Python is best for beginners? ›
Beginner - IDLE, Thonny would be the perfect choice for first-time programmers who are just getting into Python. Intermediate - For intermediate level users PyCharm, VS Code, Atom, Sublime Text 3 are good options.Which is the best book to learn Python completely? ›
- Python Crash Course: A Hands-On, Project-Based Introduction to Programming (2nd Edition) Author: Eric Matthes. ...
- Head-First Python: A Brain-Friendly Guide (2nd Edition) ...
- Learn Python the Hard Way: 3rd Edition. ...
- Python Programming: An Introduction to Computer Science (3rd Edition)
The answer to how much time it takes to learn python depends on the time you spent learning. Ask yourself how much time you can dedicate to learning and practicing Python. Generally, it is recommended to dedicate one hour every day to Python learning.