how to use zip efficiently to iterate parallelly in multiple lists-CodePudding

Is there any way that while using the ZIP function we can provide some default value to parallel elements which are not present and still print the entire stuff?

eg, for the below code 6 from list a getting missed but I don't want that to happen

a = [1,2,4,6]
b = [[1,3],[4,7],[6,1]]
for a,(b,c) in zip(a,b):
  print(a,b,c)

CodePudding user response：

You can use zip_longest to provide default values for missing elements in your code:

from itertools import zip_longest

a = [1, 2, 4, 6]
b = [[1, 3], [4, 7], [6, 1]]

for a, (b, c) in zip_longest(a, b, fillvalue=(0, 0)):
    print(a, b, c)

This will print the following output:

The zip_longest function automatically adds a default value of 0 for the missing elements in the input iterables. You can change the default value to any other value that you want to use, by specifying it in the fillvalue argument.

CodePudding user response：

The zip_longest function from itertools should achieve exactly what you want:

from itertools import zip_longest

a = [1,2,4,6]
b = [[1,3],[4,7],[6,1]]
for a,(b,c) in zip_longest(a,b, fillvalue=("NaN1", "NaN2")):
   print(a,b,c)

CodePudding user response：

from itertools import zip_longest

x = [1,2,4,6]
y = [[1,3],[4,7],[6,1]]
for x,(y,z) in zip_longest(x,y, fillvalue=("NaN1", "NaN2")):

   print(x,y,z)