Why does this work in the Python IDLE shell but not when I run it as a Python script from the command prompt?

Question

This works in the Python 3.3.2 Shell

Inside the Python 3.3.2 Shell

>>> import datetime
>>> print(datetime.datetime.utcnow())
2013         


        

Answer 1

As @Sukrit Kalra says, don't use datetime.py as your file name. Python is getting confused with which datetime is which (and is importing itself!). Maybe;

 $ mv datetime.py my_datetime.py

Answer 2

Naming your file datetime causes Python to import the file you're running as a module. For example, look at sys.path. Mine, for example, is ['', '/usr/lib/python3.3', ...], which means that Python looks FIRST in the current working directory (the '') for modules. And because anything that ends in .py can be imported as a module, it imports the script that you're actually running (which, if I'm not mistaken, actually causes it to be run twice, once as __main__ and once as a module).

Answer 3

Never use filenames same as module names. Change filename to something else apart from datetime.py .

Answer 4

The problem is that file is recursively importing itself, instead of importing the built-in module datetime:

Demo:

$ cat datetime.py
import datetime
print datetime.__file__
$ python datetime.py
/home/monty/py/datetime.pyc
/home/monty/py/datetime.pyc

This happens because the module is searched in this order:

• the directory containing the input script (or the current directory).
• PYTHONPATH (a list of directory names, with the same syntax as the shell variable PATH).
• the installation-dependent default.

Simply change the name of datetime.py to something else.