Have Python 2 And 3

Python Programming

Have you ever found yourself in a situation where you needed to work with both Python 2 and Python 3? As a developer, this is a common challenge that I have faced numerous times. In this article, I will dive deep into the topic of having Python 2 and Python 3 coexist in your development environment.


Python, a versatile and powerful programming language, has undergone a major transition from Python 2 to Python 3. However, due to various reasons such as legacy codebases or libraries that have not yet migrated, it is not uncommon to find yourself needing to work with both versions simultaneously.

The Compatibility Challenge

One of the primary challenges when working with both Python 2 and Python 3 is ensuring compatibility between the two versions. Python 2 and Python 3 have significant differences in syntax and features, which can lead to compatibility issues when trying to run code written in one version using the other.

To tackle this challenge, one approach is to use conditional statements to handle version-specific code. By checking the Python version at runtime, you can write code that behaves differently based on the version being used. This can help ensure that your code runs smoothly regardless of the Python version.

import sys

if sys.version_info.major == 2:
    # Python 2 specific code
    print("Running Python 2 code")
    # Python 3 specific code
    print("Running Python 3 code")

Another useful tool for managing compatibility is the __future__ module. This module allows you to import certain features from Python 3 into Python 2, making it easier to write code that is compatible with both versions. For example, to enable the print function from Python 3 in Python 2, you can add the following import statement at the beginning of your code:

from __future__ import print_function

Managing Packages and Environments

Another consideration when working with both Python 2 and Python 3 is managing packages and environments. Python package management tools such as pip and virtualenv can help you set up separate environments for each version.

To install packages for Python 2, you can use the following command:

pip2 install package_name

Similarly, for Python 3, you can use:

pip3 install package_name

To create a virtual environment for Python 2, you can use:

virtualenv -p python2 myenv

And for Python 3:

virtualenv -p python3 myenv

By setting up separate virtual environments, you can isolate your Python 2 and Python 3 projects, preventing any conflicts between packages or dependencies.

Migration Strategies

If you find yourself in a position where you need to migrate code from Python 2 to Python 3, there are several strategies you can adopt:

  • Manual Conversion: This involves manually going through your code and updating any syntax or features that are incompatible with Python 3. While this approach can be time-consuming, it allows for fine-grained control over the migration process.
  • Automated Tools: There are various tools available that can assist with the migration process by automatically converting Python 2 code to Python 3 syntax. These tools can save a significant amount of time and effort, but it’s important to review the converted code to ensure correctness.
  • Dual Compatibility: In some cases, it may be necessary to maintain compatibility with both Python 2 and Python 3 for an extended period. This can be achieved by using conditional statements and compatibility libraries to write code that works in both versions.

It’s important to carefully consider the specific requirements of your project and choose a migration strategy that best suits your needs.


Working with both Python 2 and Python 3 can be a complex task, but with the right approach and tools, it is possible to manage the coexistence of these two versions. By ensuring compatibility, managing packages and environments, and adopting appropriate migration strategies, you can navigate the challenges and continue to work with both Python versions effectively.