Exclude __builtin__ Module

The __builtin__ module in Python clutters a developers namespace with lots of functions and classes that have very generic names (e.g. max, sum, id, hash etc.) that often get in th

Solution 1:

You can simply delete __builtins__, the name Python uses to find the built-in namespace:

>>> del __builtins__
>>> max
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
NameError: name 'max' is not defined

Warning: If you do this in someone else's namespace, they will hate you.

...and require explicit imports instead?

Note that import statements are resolved using builtins ;)

>>> del __builtins__
>>> from builtins import max
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ImportError: __import__ not found

... very generic names (e.g. max, sum, id, hash etc.) that often get in the way of naming variables and when outside of a context-aware IDE one can accidentally overwrite a name without noticing

You will only create a local variable which shadows the name. This is actually fairly inconsequential if you do it from within a limited scope, although it's still bad form (readability counts).

# this shadows built-in hash function in this namespace ... meh?
hash = '38762cf7f55934b34d179ae6a4c80cadccbb7f0a'

# this stomps built-in hash ... not a honking great idea!
import builtins
builtins.hash = lambda obj: -1

Best practice:

• Use a context-aware editor which will give you a squiggly underline for name collisions, or
• Use Python long enough that you know the built-in names by heart (seriously!)
• Avoid name shadowing by using a synonym (e.g. checksum) or appending a trailing underscore on the name (e.g. hash_)