Python: 'module' object is not callable

Question

I have an exception class defined

#####UNIQUE CONSTRAINT EXCEPTION#########################################################3
class UniqueConstraintException (Exception):
 def __init__(self, value):
 self.value = value
 def __str__(self):
 return repr('Failed unique property. Property name: ' + self.value)

The file name is: "UniqueConstraintException.py" and package name: "exception"

I'm importing and using it in this way:

from exception import UniqueConstraintException
raise UniqueConstraintException(prop_key)

And get this error:

TypeError: 'module' object is not callable

What am i doing wrong?

• user395760: Python is not Java, that's what's wrong. You don't go around defining 4 line modules just to have a single class per file. Put your exceptions together. And for that matter, think long and hard before adding a new exception type. There's nothing wrong with the built-in ones.
• bukzor: Please read PEP8: python.org/dev/peps/pep-0008
• John Carrell: Thanks for being a phallus about it, delnan. A lot of passive aggression in there. You know, some of us don't know everything. If only we could be as knowledgeable as you. (P.S. For an additional example of passive aggression please re-read this comment)
• frei: i just wanted to comment that despite delnan's answer coming across as pretty aggressive, coming from Java, learning python and reading the blogpost that he posted after a couple weeks of study was pretty helpful in rethinking how i approach python. defining your own exceptions is rarely useful

Answer 1

This is why you want to keep your module names lower-cased. :-)

from exception.UniqueConstraintException import UniqueConstraintException

You imported the module, no the class defined inside of the module.

• Martijn Pieters: In this case? Just put all your exceptions in one exceptions.py module. In the general case, I'd name the module uniqueconstraint.py perhaps.