I have a main script, which imports another python library that I've been writing. The library contains the following command:
print getattr(__builtins__, "list")
This produces the following error when I call it from the library:
'dict' object has no attribute 'list'
But, if I copy and paste that same command into the main script it works fine. Any ideas why this isn't working?
The header of my main file looks like this:
#/usr/bin/env python
from sys import argv
import re, sys, os, argparse
sys.path.extend(map(os.path.abspath, ['C:/Users/xxxx/scripts/modules/']))
import general
The header for my "general" library is:
#!/usr/bin/env python
from sys import argv
import re, sys, os, argparse
def getBuiltin(name):
##Convert a string into an attribute
try:
return getattr(__builtins__, name)
except Exception as e:
print "Unhandled type in function \"get_builtin\""
print name
print e
exit()
I was calling the library like this:
print general.getBuiltin("list")
where, "getBuiltin" is the name of my function
You can also check this question: Python: What's the difference between __builtin__ and __builtins__?
As you can see in akent answer, builtins is different in main module and another module:
Straight from the python documentation: http://docs.python.org/reference/executionmodel.html
By default, when in the main module, builtins is the built-in module builtin (note: no 's'); when in any other module, builtins is an alias for the dictionary of the builtin module itself.
builtins can be set to a user-created dictionary to create a weak form of restricted execution.
CPython implementation detail: Users should not touch builtins; it is strictly an implementation detail. Users wanting to override values in the builtins namespace should import the builtin (no 's') module and modify its attributes appropriately. The namespace for a module is automatically created the first time a module is imported. Note that in Python3, the module builtin has been renamed to builtins to avoid some of this confusion.