CODEWITHSUNDEEP
pythonlistcount
user2006236
user2006236

Reputation: 85

Counting factors in a list?

Okay so I made a list called numbersList, a variable number = 20, count = 0, and spot = 0.

numbersList = range(1, 11)
number = 20
count = 0
spot = 0.

I want to count the numbers in the list that go into 20. I tried this:

while spot <= len(numbersList):
    if(number % int(numbersList[spot]) == 0):
        count = count + 1
    spot = spot + 1
print count

But it keeps saying list index is out of range. Please help!

Upvotes: 0

Views: 108

Answers (4)

Arcturus
Arcturus

Reputation: 548

I prefer the classic map-reduce 

 reduce( lambda x,y: x+y, [ number%spot for spot in numbersList ] )

Upvotes: 0

John La Rooy
John La Rooy

Reputation: 304137

The first line is a SyntaxError

>>> when spot <= len(numbersList):
  File "<stdin>", line 1
    when spot <= len(numbersList):

I suspect you mean to use while

But it's easier to use a for loop

for spot in numbersList:
    if number % spot == 0:
        count += 1
print count

This can also be written more simply by passing a generator expression to sum

count = sum(number % spot == 0 for spot in numbersList)

Upvotes: 1

Blender
Blender

Reputation: 298106

Your index goes too far at the last iteration of the while loop. Change the <= to < and it should work:

while spot < len(numbersList):

Or just use a for loop:

for i in numbersList:
    if number % i == 0:
        count += 1

Upvotes: 2

Ian McMahon
Ian McMahon

Reputation: 1700

You can't index into a list with a float, and spot = 0. is a float. Try removing that spurious period!

Upvotes: 1

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