This example demonstrates how to use Graph-sitter to automatically migrate Python 2 code to Python 3. For a complete walkthrough, check out our tutorial.

The migration script handles five key transformations:

1. Convert Print Statements

   # From:
   print "Hello, world!"
   print x, y, z
   
   # To:
   print("Hello, world!")
   print(x, y, z)

2. Update Unicode to str

   # From:
   from __future__ import unicode_literals
   
   text = unicode("Hello")
   prefix = "prefix"
   
   # To:
   text = str("Hello")
   prefix = "prefix"

3. Convert raw_input to input

   # From:
   name = raw_input("Enter your name: ")
   
   # To:
   name = input("Enter your name: ")

4. Update Exception Handling

   # From:
   try:
       process_data()
   except ValueError, e:
       print(e)
   
   # To:
   try:
       process_data()
   except ValueError as e:
       print(e)

5. Modernize Iterator Methods

   # From:
   class MyIterator:
       def next(self):
           return self.value
   
   
   # To:
   class MyIterator:
       def __next__(self):
           return self.value

# Install Graph-sitter
pip install graph-sitter

# Run the migration
python run.py

The script will process all Python files in the repo-before directory and apply the transformations in the correct order.

• run.py - The migration script
• input_repo/ - Sample Python 2 code to migrate

• Full Tutorial
• Python 3 Documentation
• What's New in Python 3
• Graph-sitter Documentation