Python 2 and Python 3 are both widely used versions of the Python programming language, but they have some key differences.
Syntax: One of the most notable differences is syntax. For example, in Python 2, the print statement is used without parentheses, whereas in Python 3, it requires parentheses. Additionally, in Python 3, the division operator (/) always returns a float, whereas in Python 2 it returns an integer if both operands are integers.
Standard Library: Python 3 includes a number of new modules and improvements to existing modules, such as improved handling of text and binary data, new libraries for asynchronous execution, and new libraries for working with network protocols.
Unicode: Python 3 uses Unicode for strings by default, whereas Python 2 uses ASCII. This means that in Python 3, all strings are Unicode by default, whereas in Python 2, strings are ASCII by default and need to be explicitly marked as Unicode.
Exception Handling: Python 3 introduces a "raise from" statement, which allows you to specify the original exception that caused an exception to be raised. In Python 2, chaining exceptions was less elegant and required multiple lines of code.
Integer Division: In Python 2, the division operator (/) returns an integer if both operands are integers, whereas in Python 3 it returns a float. This can lead to confusion for developers who are used to the behavior in Python 2.
Functionalities Deprecated: Some functionalities that were present in Python 2 have been deprecated in Python 3, such as the "exec" statement, the "apply()" function, and the "backtick" operator.
Overall, Python 3 is the future of the language, and it is recommended to use it for new projects. However, many legacy codebases are still written in Python 2, so it is still in use today.
Another difference between Python 2 and Python 3 is the handling of exceptions. In Python 2, when an exception is caught, it is immediately cleared, so it cannot be re-raised or inspected later. Python 3 introduced the "raise from" statement, which allows you to specify the original exception that caused an exception to be raised, and makes it possible to re-raise or inspect the original exception.
Additionally, Python 3 introduced a number of new built-in functions, such as "ascii()", "hex()", "oct()" and "bin()" for working with numbers, "print()" function which is a built-in function for printing output to the console, and "input()" function for getting input from the user.
Python 3 also introduced a number of new data types, such as "bytes" and "bytearray" for working with binary data, and "memoryview" for working with memory in a more efficient way.
It's also worth noting that in Python 3, the "range()" function returns an iterator, whereas in Python 2 it returns a list. This can lead to a significant performance improvement in situations where you're working with large ranges of numbers.
Lastly, Python 3 also introduced a number of new syntax features, such as "f-strings" (formatted string literals) which allows you to embed expressions inside string literals, and the "walrus operator" (:=) which allows you to assign a value to a variable as part of an expression.
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