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How to sum all the values in a dictionary?

Let's say I have a dictionary in 开发者_如何学Pythonwhich the keys map to integers like:

d = {'key1': 1,'key2': 14,'key3': 47}

Is there a syntactically minimalistic way to return the sum of the values in d—i.e. 62 in this case?


As you'd expect:

sum(d.values())


In Python 2 you can avoid making a temporary copy of all the values by using the itervalues() dictionary method, which returns an iterator of the dictionary's keys:

sum(d.itervalues())

In Python 3 you can just use d.values() because that method was changed to do that (and itervalues() was removed since it was no longer needed).

To make it easier to write version independent code which always iterates over the values of the dictionary's keys, a utility function can be helpful:

import sys

def itervalues(d):
    return iter(getattr(d, ('itervalues', 'values')[sys.version_info[0]>2])())

sum(itervalues(d))

This is essentially what Benjamin Peterson's six module does.


Sure there is. Here is a way to sum the values of a dictionary.

>>> d = {'key1':1,'key2':14,'key3':47}
>>> sum(d.values())
62


d = {'key1': 1,'key2': 14,'key3': 47}
sum1 = sum(d[item] for item in d)
print(sum1)

you can do it using the for loop


I feel sum(d.values()) is the most efficient way to get the sum.

You can also try the reduce function to calculate the sum along with a lambda expression:

reduce(lambda x,y:x+y,d.values())


sum(d.values())

  • "d" -> Your dictionary Variable


USE sum() TO SUM THE VALUES IN A DICTIONARY.

Call dict.values() to return the values of a dictionary dict. Use sum(values) to return the sum of the values from the previous step.

d = {'key1':1,'key2':14,'key3':47}
values = d.values()
#Return values of a dictionary    
total = sum(values)
print(total)


phihag's answer (and similar ones) won't work in python3.

For python 3:

d = {'key1': 1,'key2': 14,'key3': 47}
sum(list(d.values()))

Update! There are complains that it doesn't work! I just attach a screenshot from my terminal. Could be some mismatch in versions etc.

How to sum all the values in a dictionary?


You could consider 'for loop' for this:

  d = {'data': 100, 'data2': 200, 'data3': 500}
  total = 0
  for i in d.values():
        total += i

total = 800


simplest/silliest solution:

https://trinket.io/python/a8a1f25353

d = {'key1': 1,'key2': 14,'key3': 47}
s = 0
for k in d:
    s += d[k]

print(s)

or if you want it fancier:

https://trinket.io/python/5fcd379536

import functools

d = {'key1': 1,'key2': 14,'key3': 47}
s = functools.reduce(lambda acc,k: acc+d[k], d, 0)

print(s)


You can get a generator of all the values in the dictionary, then cast it to a list and use the sum() function to get the sum of all the values.

Example:

c={"a":123,"b":4,"d":4,"c":-1001,"x":2002,"y":1001}

sum(list(c.values()))
0

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