CODEWITHSUNDEEP
pythonloops
user3023315
user3023315

Reputation: 55

How to sum items in a for loop in python?

I have the following code:

dict = {
    'a': 1, 'b': 3, 'c': 3, 'd': 2, 'e': 1, 'f': 4, 'g': 2, 'h': 4, 'i': 1, 
    'j': 8, 'k': 5, 'l': 1, 'm': 3, 'n': 1, 'o': 1, 'p': 3, 'q': 10, 
    'r': 1, 's': 1, 't': 1, 'u': 1, 'v': 4, 'w': 4, 'x': 8, 'y': 4, 'z': 10
}

word = 'banana'

for letter in word:
     print dict[letter]

I get the following output

3
1
1
1
1

How can I add these values?

That is how can I print the output as 8

Upvotes: 0

Views: 203

Answers (2)

kyle k
kyle k

Reputation: 5512

Here is another way that you can sum the items in the list.

dict = {
    'a': 1, 'b': 3, 'c': 3, 'd': 2, 'e': 1, 'f': 4, 'g': 2, 'h': 4, 'i': 1,
    'j': 8, 'k': 5, 'l': 1, 'm': 3, 'n': 1, 'o': 1, 'p': 3, 'q': 10,
    'r': 1, 's': 1, 't': 1, 'u': 1, 'v': 4, 'w': 4, 'x': 8, 'y': 4, 'z': 10
}

word = 'banana'
sum = 0
for letter in word:
    sum+=dict[letter]
print sum

Upvotes: 0

user2555451
user2555451

Reputation:

You can use sum and a generator expression:

>>> # Please don't name a variable `dict` -- it overshadows the built-in
>>> dct = { 'a': 1, 'b': 3, 'c': 3, 'd': 2, 'e': 1, 'f': 4, 'g': 2, 'h': 4, 'i': 1, 'j': 8, 'k': 5, 'l': 1, 'm': 3, 'n': 1, 'o': 1, 'p': 3, 'q': 10, 'r': 1, 's': 1, 't': 1, 'u': 1, 'v': 4, 'w': 4, 'x': 8, 'y': 4, 'z': 10 }
>>> word = 'banana'
>>> print sum(dct[letter] for letter in word)
8
>>>

Note that the above solution assumes that all of the characters in word can be found in dct. If this isn't always the case, then you can use dict.get to avoid a KeyError:

>>> dct = { 'a': 1, 'b': 3, 'c': 3, 'd': 2, 'e': 1, 'f': 4, 'g': 2, 'h': 4, 'i': 1, 'j': 8, 'k': 5, 'l': 1, 'm': 3, 'n': 1, 'o': 1, 'p': 3, 'q': 10, 'r': 1, 's': 1, 't': 1, 'u': 1, 'v': 4, 'w': 4, 'x': 8, 'y': 4, 'z': 10 }
>>> word = '$banana1'
>>> print sum(dct.get(letter, 0) for letter in word)
8
>>>

Upvotes: 6

Related Questions