How to use a different function at each iteration

Question

Instead of writing the same line for each function (as shown in the first code block), I want to call each function with the help of a loop (as shown in the 2nd code block)

What I want to be able to do is:

import numpy as np
A = np.arange(9).reshape(3,3)
B = np.array([3,4,6,3,2,7,0,1,7]).reshape(3,3)
#################

def calc_stats(mat):
    print(mat.max())
    print(mat.min())
    print(mat.mean())

calc_stats(A)
calc_stats(B)

But by the use of a loop where at each iteration I can change the name of the function.
Something similar to this:

import numpy as np
A = np.arange(9).reshape(3,3)
B = np.array([3,4,6,3,2,7,0,1,7]).reshape(3,3)
#################

def calc_stats(mat):
    for names in ["mean", "max", "min"]:
        print(mat.names())

calc_stats(A)
calc_stats(B)

Of course, the above code doesn't work because a variable cannot be used as a function name, but is there any method to implement what I want to do?

This question got closed the last time I posted it because it seemed similar to this question, but I'm finding the answers provided in this post a bit hard to understand or relate to my question.

Cory Kramer · Answer 1 · 2021-03-05T19:28:47.723

2

You can keep a list of functions to call, the call each one on the provided argument

def calc_stats(mat):
    for f in [np.mean, np.max, np.min]:
        print(f(mat))

Output

>>> calc_stats(A)
4.0
8
0
>>> calc_stats(B)
3.6666666666666665
7
0

edited Mar 05 '21 at 19:28

answered Mar 05 '21 at 18:39

Cory Kramer

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Won't this become very specific, then? I won't be able to use it for variables other than A, I think. – ray_lv Mar 05 '21 at 18:42
@ray_lv Then use a function def all_functions(b): for f in [b.mean, b.max, b.min]: print(f()) – Max de Boer Mar 05 '21 at 18:48
@ray_lv If this is not general enough for your use case can you edit your question with an more specific example of what you're trying to do? – Cory Kramer Mar 05 '21 at 18:49
I've made some edits for more clarification about how I should be able to use different variables as well. – ray_lv Mar 05 '21 at 19:22
1

@ray_lv I've edited my answer, is this closer to what you're looking for? – Cory Kramer Mar 05 '21 at 19:29

score 1 · Accepted Answer · answered Mar 05 '21 at 19:31

1

If you must use strings for the names you can obtain the functions using getattr():

def calc_stats(mat):
    for name in ["mean", "max", "min"]:
        print(getattr(np,name)(mat))

output:

calc_stats(A)
4.0
8
0

calc_stats(B)
3.6666666666666665
7
0

answered Mar 05 '21 at 19:31

Alain T.

40,517
4
31
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How to use a different function at each iteration

2 Answers2