Python2 vs Python3

Beginning Python users are confused to choose which version is better for learning. The most common used versions of Python are Python 2.x and Python 3.x. Python 2 is for legacy and Python 3 is the future of programming language.  Both versions are almost similar and easy to learn. But, there are plenty of differences between these Python versions.

1. Division

Python 3 has improved division operator. By using Python 3 you will get expected result without any worry.

But, in the case of Python 2 , if you use division operator in your calculation it rounds down to the nearest whole number.

For example,

Your expected answer is 2.5 . But the Python 2 gives only  integer back when you input only integers. That is the answer in 2 in the case of Python 2.

In order to get the result 2.5, you would have to write 5.0/2.0 to tell Python that you want it to return a float, that is, to include digits after the decimal point in the result.

Python 3:

2. Print Statement

The most well known difference in Python 2 and Python 3 is print statement. Python 2 uses print statement and Python 3 uses print method. It will be dangerous when you put the print statement in Python 2 to Python 3.It becomes a syntax error.

In python 2 you can write print statement simply :

The difference in Python 3 is just use an additional parenthesis  to print the statement, as follows:

But there is no issue when you use parenthesis to print statement in Python 2.x versions.

3.Unicode

In Python 3, there is better Unicode support . Unicode Strings can store different language letters ,Roman numbers,symbols etc.,

In Python 2, implicitly string type is ASCII by default.

Output in Python 2,same output for string and bytes:

Output in Python 3,different for bytes and strings:

Python 2 also support Unicode.

Output in Python 2,Unicode and Strings are different:

Output in Python 3,Unicode and strings are same:

4. Exception Handling

There is a slight difference in Error handling in both versions. In python 3 we have to use “as” keyword

Python 2 :

Output :

Python 3 :

Output :

5. User Input Method

The user input method problem in Python 2 is fixed in Python 3.

In the case of Python 3 ,input() always receives input as ‘str’ or string type. In Python 2 there are two methods raw_input() and input() method.

It is recommended that use raw_input() method to read other type than Strings to avoid complications.

Python 2:

Python 3:

6. Xrange

The range in Python 3 is more power full than range in Python 2.

In Python 2 the range function return a list as follows:

And the xrange returns iterator object that gives the same thing when looping over. This behavior is similar to lazy evaluation.

This laziness is improved in Python 3 by removing the original range function and renamed x range to range

_future_  Module:

This is the idea of merging Python 3 code to Python 2 code. This not referred to as the difference between two versions. If you want to  support Python 3 in Python 2 code by importing _future_ module .

Division in Python 2 works same as Python 3 in below given code:

Output:

Hope you understood the concept of Python2 vs Python3..