How do I check if a variable exists in python

Question

I want to check if a variable exists. Now I'm doing something like this:

try:
   myVar
except NameError:
   # Do something.

Are there other ways without exceptions?

Answer 1

Variables in Python can be defined locally or globally. There are two types of the variable first one is a local variable that is defined inside the function and the second one are global variable that is defined outside the function.

To check the existence of the variable locally we are going to use the locals() function to get the dictionary of the current local symbol table.

Example:
Examples: Checking local variable existence

def func():        # defining local variable     a_variable = 0        # using locals() function      # for checking existence in symbol table     is_local_var = "a_variable" in locals()        # printing result     print(is_local_var)    # driver code func()

Output:

True

Answer 2

Python doesn’t have a specific function to test whether a variable is defined, since all variables are expected to have been defined before use, even if initially assigned the None object.