How can I find the most negative key in a python dictionary?

Question

I am trying to find the most positive and most negative values in the dictionary imdb_dict:

imdb_dict = {'the': '0.0490972013402',
 'and': '0.201363575849',
 'a': '0.0333946807184',
 'of': '0.099837669572',
 'to': '-0.0790210365788',
 'is': '0.188660139871',
 'it': '0.00712569582356',
 'in': '0.109215821589',
 'i': '-0.154986397986'}

Using the code found here: Getting key with maximum value in dictionary?

I can obtain the maximum value of the dictionary using:

import operator
max(imdb_dict.items(), key=operator.itemgetter(1))

However, I cannot find a way to get the most negative value in the dictionary as using min shows the value closest to 0. Is there a way to modify the operator to get the maximum negative value or an easier way to accomplish the same?

your values are strings. min will work fine if they are converted to numbers for numerical comparison. — Paritosh Singh, Jun 11 '19 at 12:05
[`min()`](https://docs.python.org/3/library/functions.html#min)? — Olvin Roght, Jun 11 '19 at 12:05
If you are looking for value, then take a look at https://stackoverflow.com/questions/16099112/how-to-return-smallest-value-in-dictionary — brechmos, Jun 11 '19 at 12:06
thank you for catching my blunder. I completely missed the datatype that was being imported from the text file — notlaughing, Jun 11 '19 at 12:21

yatu · Accepted Answer · 2019-06-11T12:22:25.810

The issue here is that the values are strings, so the ordering is lexicographical. You'd need a lambda function to take the min over the values in the dictionary as floats:

min(imdb_dict.items(), key=lambda x: float(x[1]))
# ('i', '-0.154986397986')

Note that by doing:

'-0.154986397986' < '-0.0790210365788'

You get False, as this is just checking what position a given character occupies in the ASCII table to discern which is the lowest. Hence the character that will decide which string is lowest will be where the first difference takes place, in this case the digit right after the dot, i.e 1 and 0.

score 0 · Answer 2 · answered Jun 11 '19 at 12:12

imdb_dict = {'the': '0.0490972013402',
 'and': '0.201363575849',
 'a': '0.0333946807184',
 'of': '0.099837669572',
 'to': '-0.0790210365788',
 'is': '0.188660139871',
 'it': '0.00712569582356',
 'in': '0.109215821589',
 'i': '-0.154986397986'}

min_val = min(map(lambda x:float(x), imdb_dict.values()))
key = [i for i in imdb_dict.keys() if imdb_dict[i]==min_val]

print(key)
# output 'i'

score 0 · Answer 3 · answered Jun 11 '19 at 12:12

Here

imdb_dict = {'the': '0.0490972013402',
             'and': '0.201363575849',
             'a': '0.0333946807184',
             'of': '0.099837669572',
             'to': '-0.0790210365788',
             'is': '0.188660139871',
             'it': '0.00712569582356',
             'in': '0.109215821589',
             'i': '-0.154986397986'}

for i, k in enumerate(imdb_dict.keys()):
    if i == 0:
        _min = (float(imdb_dict[k]), k)
    else:
        if float(imdb_dict[k]) < _min[0]:
            _min = (float(imdb_dict[k]), k)
print(_min)

output

(-0.154986397986, 'i')

How can I find the most negative key in a python dictionary?

3 Answers3