Why were True and False changed to keywords in Python 3

by

Possibly because Python 2.6 not only allowed True = False but also allowed you to say funny things like:

__builtin__.True = False

which would reset True to False for the entire process. It can lead to really funny things happening:

>>> import __builtin__
>>> __builtin__.True = False
>>> True
False
>>> False
False
>>> __builtin__.False = True
>>> True
False
>>> False
False

EDIT: As pointed out by Mike, the Python wiki also states the following under Core Language Changes:

  • Make True and False keywords.
    • Reason: make assignment to them impossible.

More Related Contents:

  1. Normal arguments vs. keyword arguments
  2. Passing a dictionary to a function as keyword parameters
  3. How to add builtin functions?
  4. How do I use a keyword as a variable name?
  5. How to use “raise” keyword in Python [duplicate]
  6. Finding words after keyword in python [duplicate]
  7. Python: SyntaxError: keyword can’t be an expression
  8. How to execute my code block by block?
  9. Are a WSGI server and HTTP server required to serve a Flask app?
  10. Sending data from HTML form to a Python script in Flask
  11. MySQL parameterized queries
  12. Simpler way to create dictionary of separate variables?
  13. Read Excel cell value and not the formula computing it -openpyxl
  14. What’s the deal with Python 3.4, Unicode, different languages and Windows?
  15. Seaborn Barplot – Displaying Values
  16. SQLAlchemy: unexpected results when using `and` and `or`
  17. type object ‘datetime.datetime’ has no attribute ‘datetime’
  18. How do I maximize the display screen in PyGame?
  19. Can’t pickle defaultdict
  20. Python selenium keep browser open
  21. Fill countries in python basemap
  22. Can’t install mysql-python (newer versions) in Windows
  23. python re.sub, only replace part of match [duplicate]
  24. Mock Python’s built in print function
  25. How to pad a string with leading zeros in Python 3 [duplicate]
  26. Dump a list in a pickle file and retrieve it back later [closed]
  27. How to do multiple arguments with Python Popen?
  28. How to use Flask-Script and Gunicorn
  29. Setting a fixed FPS in Pygame, Python 3
  30. Remote connection to MS SQL – Error using pyodbc vs success using SQL Server Management Studio

Leave a Comment