I'd like to run a function from IPython and load all of its data into the interactive namespace, just like how %run filename.py does it. E.g., here's the file scratch.py:
def foo(x):
a = x*2
In IPython, I'd like to run this function and be able to access the name a. Is there a way to do this?
In order to make the variable available globally (or in some interactive IPython session), you first have to define it as global:
def foo(x):
global a
a = x*2
Otherwise your a remains a local variable within your function. More infos e.g. here: Use of “global” keyword in Python
This isn't a ipython or %run issue, but rather a question of what you can do with variables created with a function. It applies to any function run in Python.
A function has a local namespace, where it puts the variables that you define in that function. That is, by design, local to the function - it isn't supposed to 'bleed' into the calling namespare (global of the module or local of the calling function). This is a major reason from using functions - to isolate it's variables from the calling one.
If you need to see the variables in a function you can do several things:
This is a useless function:
def foo(x):
a = x*2
this may have some value
def foo(x):
a = x*2
return a
def foo(x):
a = x*2
print(a) # temporary debugging print
# do more with a and x
return ...
In a clean design, a function takes arguments, and returns values, with a minimum of side effects. Setting global variables is a side effect that makes debugging your code harder.
