Function returning a dictionary with string lengths (keys) and number of occurrence (values) from a list

Question

I am trying to write a function that takes a list of strings and returns a dictionary where the keys represent a length and the values represent how many strings have that length in the list. This is what I have written and my output:

def length_counts(stringList):
stringDict = {}
for value in stringList:
stringDict[len(value)] = stringList.count(value)
return stringDict

#test
sa_countries = ["Brazil", "Venezuela", "Argentina", "Ecuador", "Bolivia", "Peru"]
print(length_counts(sa_countries))

#output
{6: 1, 9: 1, 7: 1, 4: 1}

Correct output should be: {6: 1, 9: 2, 7: 2, 4: 1}

Which says there is 1 string with 6 letters, 2 strings with 9 letters, 2 strings with 7 letters, and 1 string with 4 letters.

Thank you.

Answer 1

This a solution using comprehensions:

sa_countries = ["Brazil", "Venezuela", "Argentina", "Ecuador", "Bolivia", "Peru"]
lens = [len(i) for i in sa_countries]
print(*[{x:lens.count(x)} for x in set(lens)])

# output: {9: 2} {4: 1} {6: 1} {7: 2}

Answer 2

Here is also a version with for loops:

def length_counts(stringList):
stringDict = {}
lens = []
res = {}
for i in stringList:
lens.append(len(i))
for j in set(lens):
res.update({j:lens.count(j)})
return res

sa_countries = ["Brazil", "Venezuela", "Argentina", "Ecuador", "Bolivia", "Peru"]
print(length_counts(sa_countries))

Answer 3

You can obtain a previous count for a specified length and increment it.

https://code.sololearn.com/cn1Kd6Kee2O4/?ref=app

Answer 4

stringList.count(value)
will only return how many times a country is repeated in the string list.

Answer 5

try this.
https://code.sololearn.com/c4667NQuovAe/?ref=app

Answer 6

Thanks @Bahha

Answer 7

Lothar thank you