What is the problem with this simple code using map function in python?

Question

Code is as follows:

def func(i,j):
    return i+j

m = list(product(range(5),range(7)))
print(m)
x = map(func,m)
list(x)

Error :

[(0, 0), (0, 1), (0, 2), (0, 3), (0, 4), (0, 5), (0, 6), (1, 0), (1, 1), (1, 2), (1, 3), (1, 4), (1, 5), (1, 6), (2, 0), (2, 1), (2, 2), (2, 3), (2, 4), (2, 5), (2, 6), (3, 0), (3, 1), (3, 2), (3, 3), (3, 4), (3, 5), (3, 6), (4, 0), (4, 1), (4, 2), (4, 3), (4, 4), (4, 5), (4, 6)]
---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-181-fdda131ed5e8> in <module>()



      5 print(m)
      6 x = map(func,m)
----> 7 list(x)

TypeError: func() missing 1 required positional argument: 'j'

How to pass each pair in m through func . I don't want any for loop.

Answer 1

You can use itertools.starmap :

from itertools import product, starmap

def func(i,j):
    return i+j

m = list(product(range(5),range(7)))
print(m)
x = starmap(func,m)
list(x)

Answer 2

...or you need to define func() differently:

def func(i):
    return i[0]+i[1]

In your definition ( func(i,j) ), you pass func() two arguments (i, j) , but you map() func() only to only argument (a tuple). If you change your definition of func(), where you pass it an iterator, it should work.