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Python: Merge more than one dictionary in a single expression

Python Collections: Exercise-18 with Solution

Write a Python program to merge more than one dictionary in a single expression.

Sample Solution:

Python Code:

import collections as ct
def merge_dictionaries(color1,color2):
    merged_dict = dict(ct.ChainMap({}, color1, color2))
    return merged_dict
color1 = { "R": "Red", "B": "Black", "P": "Pink" }
color2 = { "G": "Green", "W": "White" }
print("Original dictionaries:")
print(color1,' ',color2)
print("\nMerged dictionary:")
print(merge_dictionaries(color1, color2))

def merge_dictionaries(color1,color2, color3):
    merged_dict = dict(ct.ChainMap({}, color1, color2, color3))
    return merged_dict

color1 = { "R": "Red", "B": "Black", "P": "Pink" }
color2 = { "G": "Green", "W": "White" }
color3 = { "O": "Orange", "W": "White", "B": "Black" }

print("\nOriginal dictionaries:")
print(color1,' ',color2, color3)
print("\nMerged dictionary:")
# Duplicate colours have automatically removed.
print(merge_dictionaries(color1, color2, color3))

Sample Output:

Original dictionaries:
{'R': 'Red', 'B': 'Black', 'P': 'Pink'}   {'G': 'Green', 'W': 'White'}

Merged dictionary:
{'B': 'Black', 'R': 'Red', 'P': 'Pink', 'G': 'Green', 'W': 'White'}

Original dictionaries:
{'R': 'Red', 'B': 'Black', 'P': 'Pink'}   {'G': 'Green', 'W': 'White'} {'O': 'Orange', 'W': 'White', 'B': 'Black'}

Merged dictionary:
{'B': 'Black', 'R': 'Red', 'P': 'Pink', 'G': 'Green', 'W': 'White', 'O': 'Orange'}

Flowchart:

Python Collections: Merge more than one dictionary in a single expression.

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Python Code Editor:

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Python: Tips of the Day

Creates a dictionary with the same keys as the provided dictionary and values generated by running the provided function for each value:

Example:

def tips_map_values(obj, fn):
  ret = {}
  for key in obj.keys():
    ret[key] = fn(obj[key])
  return ret
users = {
  'Owen': { 'user': 'Owen', 'age': 29 },
  'Eddie': { 'user': 'Eddie', 'age': 15 }
}

print(tips_map_values(users, lambda u : u['age'])) # {'Owen': 29, 'Eddie': 15}

Output:

{'Owen': 29, 'Eddie': 15}