python dictionary multiple keys code example

Example 1: python dictionary multiple same keys

No, each key in a dictionary should be unique. 
You can’t have two keys with the same value. 
Attempting to use the same key again will just overwrite the previous value stored. 
If a key needs to store multiple values, 
then the value associated with the key should be a list or another dictionary.
Sourece: https://discuss.codecademy.com/t/can-a-dictionary-have-two-keys-of-the-same-value/351465

Example 2: how to have multiple values to a key in dict in python

from collections import defaultdict
 data = [(2010, 2), (2009, 4), (1989, 8), (2009, 7)]
 d = defaultdict(list)
print (d) # output --> defaultdict(<type 'list'>, {})
 for year, month in data:
     d[year].append(month) 
print (d) # output --> defaultdict(<type 'list'>, {2009: [4, 7], 2010: [2], 1989: [8]})

Example 3: combine two dictionary adding values for common keys

a = {
    "a": 1,
    "b": 2,
    "c": 3
}

b = {
    "a": 2,
    "b": 3,
    "d": 5
}

# Python 3.5

for key in b:
    if key in a:
        b[key] = b[key] + a[key]

c = {**a, **b}
print(c)

>>> c
{'a': 3, 'b': 5, 'c': 3, 'd': 5}

Example 4: how to create multiple dictionaries in python

import string
for name in ["lloyd", "alice", "tyler"]:
    name = {"name": string.capitalize(name), "homework": [], "quizzes": [], "tests": []}

Example 5: how to use multiple keys for single value in dictionary python

#Python Dictionary only contain one key : one value pair.
#You can surely have multiple keys having same value
#Example :-
  dict = {'a':'value1', 'b':'value2', 'c':'value 3'}
#In above we have a and b key having same values