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Python: Group a sequence of key-value pairs into a dictionary of lists

Python Collections: Exercise-35 with Solution

Write a Python program to group a sequence of key-value pairs into a dictionary of lists.

Sample Solution:

Python Code:

from collections import defaultdict
class_roll = [('v', 1), ('vi', 2), ('v', 3), ('vi', 4), ('vii', 1)]
d = defaultdict(list)
for k, v in class_roll:
    d[k].append(v)
print(sorted(d.items()))

Sample Output:

[('v', [1, 3]), ('vi', [2, 4]), ('vii', [1])]

Flowchart:

Python Collections: Group a sequence of key-value pairs into a dictionary of lists.

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Previous: Write a Python program to create an instance of an OrderedDict using a given dictionary. Sort the dictionary during the creation and print the members of the dictionary in reverse order.
Next: Write a Python program to compare two unordered lists (not sets).

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Python: Tips of the Day

Creating a sequence of numbers (zero to ten with skips):

>>> range(0,10,2)
[0, 2, 4, 6, 8]  

 





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