Evaluating A List Of Python Lambda Functions Only Evaluates The Last List Element

I have a list of lambda functions I want to evaluate in order. I'm not sure why, but only the last function gets evaluated. Example below: >>> def f(x,z): ... prin

Solution 1:

The lambda is just looking up the global value of 'i'.

Try the following instead:

for i in range(0,5):
  lst.append(lambda x, z=i: f(x,z))

Solution 2:

try using partial, works for me:

from functools import partial

deff(x,z):
    print"x=",x,", z=",z

lst = [ partial(f,z=i) for i inrange(5) ]

for fn in lst:
    fn(3)

http://docs.python.org/library/functools.html#functools.partial

Solution 3:

Not a Python expert, but is it possible that Python is treating i in

lst.append(lambda x: f(x,i))

as a reference? Then, after the loop, i is equal to its last assigned value (4), and when the functions are called, they follow their i reference, find 4, and execute with that value.

Disclosure: probably nonsense.