Python | Get sum of tuples having same first value

Given a list of tuple, the task is to sum the tuples having same first value.

Examples:

Input: [(1, 13), (2, 190), (3, 82), (1, 12)]
Output: [(1, 25), (2, 190), (3, 82)]

Input: [(1, 13), (1, 190), (3, 25), (1, 12)]
Output: [(1, 215), (3, 25)]

 
Let’s discuss the different ways we can do this task.

Method #1: Using map()

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# Python code to get sum of tuples having same first value
  
# Initialisation of list of tuple
Input = [(1, 13), (1, 190), (3, 25), (1, 12)]
  
d = {x:0 for x, _ in Input}
  
for name, num in Input: d[name] += num
  
# using map
Output = list(map(tuple, d.items()))
  
# printing output
print(Output)

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Output:

[(1, 215), (3, 25)]

 
Method #2: Using defaultdict

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# Python code to sum list of tuples having same first value
  
# Importing
from collections import defaultdict
  
# Initialisation of list of tuple
Input = [(2, 190), (1, 13), (1, 12), 
         (2, 14), (3, 82), (1, 70)]
  
# Initialisation of defaultdict
output = defaultdict(int)
  
for k, v in Input:
    output[k] += v
  
# Printing output
print(list(output.items()))

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Output:

[(1, 95), (2, 204), (3, 82)]


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