Check undefined variable

[John Hunter]

>>>>> "Michael" == Michael Grabietz <michael.grabietz at img-online.de> writes:

    Michael> Hi, how is it possible to check whether a variable 'a' is
    Michael> undefined or not.

The namespace is stored in a dictionary that maps variable names to
values.  You can access the namespace with the functions globals() and
locals().  Since these return a dictionary, you can use the method
has_key() to see if the name exists

>>> globals().has_key('a')
0
>>> locals().has_key('a')
0
>>> a = 1
>>> globals().has_key('a')
1
>>> locals().has_key('a')
1


John Hunter