Reloading on the fly: was: Re: Python Productivity over C++

[James Logajan]

Boudewijn Rempt wrote:
> Could you post an example of designing the main program to reload
> submodules? I'd like to get that working, too, and coming from
> languages where that's impossible, I've a bit of trouble coming up
> with a solution...

Several ways are possible. Here is one way. In the main program you might
have:


# main.py
# Run-time modify of a module.
import sys
import os
import m1
m1.F(1) # Try first version of m1.py
del sys.modules['m1']  # The magic bit.
print "Please edit m1.py; press return when ready."
sys.stdin.readline()
import m1
m1.F(1) # Try second version of m1.py

And the module to be modified looks like:

# m1.py
def F(score):
    print "Banana"
    #print "Mango"

Now a typical run with commenting out the first pritn and uncommenting the
second print in m1.py should lead to an output like:

Banana
Please edit m1.py; press return when ready.

Mango


Hope this helps!

P.S. If you don't even know the name of the module ahead of time, you can
get creative with the "exec" statement!