What is the history behind capitalization of None, True and False in Python?

Question

Python has some of the value-like objects capitalized: True, False, None.

>>> type(True)
<type 'bool'>
>>> type(None)
<type 'NoneType'>
>>>

As the current PEP-8 style guide recommends writing instances and variable names in lowercase, what is the history behind writing these value-like objects capitalized?

As it is answered / commented that built-ins are capitalized, but what is the rationale and inspiration behind this? In most languages built-ins are all uppercase, so one would expect Python to follow this paradigm?

Ah, found this answer pointing to a dead link http://stackoverflow.com/a/521509/315168 — Mikko Ohtamaa, Dec 28 '13 at 23:30
In which most languages? I can actually think of only one mainstream language where built-in or standard non-types are CamelCase, C#, and it's only because it has almost everything CamelCase. — Jan Hudec, Dec 28 '13 at 23:34
None, True, and False may be capitalized since you can assign them to variables? — Macintosh Fan, Jul 13 '20 at 06:45

SevenBits · Answer 1 · 2013-12-28T23:34:26.410

5

The goal of Python is consistency within itself, not consistency to other languages. True and False are capitalized because most, if not all, built in constants are capitalized. While I am not aware of exactly why it is done, it is probably because it is easier to differentiate them from variables when the first letter is capitalized, as if it is lowercase, it is easy to confuse it with a variable.

edited Dec 28 '13 at 23:34

answered Dec 28 '13 at 23:26

SevenBits

2,836
1
20
33

Please see the clarification in the question – Mikko Ohtamaa Dec 28 '13 at 23:29

What is the history behind capitalization of None, True and False in Python?

1 Answers1