Get locals from calling namespace in Python

python metaprogramming
Peter picture Peter · Jul 8, 2011 · Viewed 8.9k times · Source

I want to retrieve the local variables from Python from a called function. Is there any way to do this? I realize this isn't right for most programming, but I am basically building a debugger. For example:

def show_locals():
  # put something in here that shows local_1.

local_1 = 123
show_locals()  # I want this to show local_1.

What do I put in the body of show_locals? If I have to modify the calling statement, what is the minimal modification I can make?

Note: this must work when show_locals is in a different module to its caller.

Answer

Gareth Rees picture Gareth Rees · Jul 8, 2011

If you're writing a debugger, you'll want to make heavy use of the inspect module:

def show_callers_locals():
    """Print the local variables in the caller's frame."""
    import inspect
    frame = inspect.currentframe()
    try:
        print(frame.f_back.f_locals)
    finally:
        del frame

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