## Example - Find the indices in a list where the item is a multiple of 7
def multiple_7(l):
indices_7 = []
for i in range(len(l)):
if(i%7 == 0):
indices_7 += [i]
return indices_7 ## list of all indices where the item is a multiple of 7
l = [2, 3, 7, 4, 14, 9] ## multiple_7 should return [2, 4]
print(multiple_7(l))
I get output [0] which is obviously not right...
You need to check the i-th element inside l not the index number i itself:
def multiple_7(l):
indices_7 = []
for i in range(len(l)):
if l[i] % 7 == 0: # <---fixed here
indices_7.append(i)
return indices_7 ## list of all indices where the item is a multiple of 7
l = [2, 3, 7, 4, 14, 9]
print(multiple_7(l))
Output:
[2,4]
You can also shorten your code to:
def multiple_7(l):
return [i for i,v in enumerate(l) if v%7==0]
Any time you need the index (and value) of something in a list, use enumerate
Read more about list comprehensions with condition here: if/else in a list comprehension?
