Count the Number of Occurrences of a Key-Value Pair in a Text File - Python

Last Updated : 9 Jan, 2026

Given a text file containing several key-value pairs in the format key = value, find how many times a specific key-value pair occurs in the file. For Example:

Input file: name=Jennie
age=25
name=Jennie
city=New York
name=Lisa

Input: key=name, value= Jennie
Output: Occurrences of 'name=Jennie' : 2

Below is a sample text file used in this article:

file1
file.txt

Now, Let's explore different methods to count the number of occurrences of a key value pair in a text file.

Using collections.Counter

This method uses Python’s Counter to easily count how many times each key-value pair appears in the file.

Python 
from collections import Counter

k = "name"
v = "Harry"

with open("file.txt", "r") as f:
    lines = [line.strip() for line in f if line.strip()]

counts = Counter(lines)
target = k + "=" + v
print("Occurrences of '" + target + "':", counts.get(target, 0))

Output

Occurrences of 'name=Harry': 3

Explanation:

  • [line.strip() for line in f if line.strip()]: Reads all lines, removes whitespace, ignores empty lines.
  • Counter(lines): Counts occurrences of each line.
  • counts.get(target,0): Retrieves the count of the specific key-value pair, defaults to 0 if not present.

Using a Manual Counter

This method reads the file line by line and increments a counter whenever the target key-value pair is found.

Python 
k = "name"
v = "Harry"
count = 0

with open("file.txt", "r") as f:
    for line in f:
        if line.strip() == k + "=" + v:
            count = count + 1

print("Occurrences of '" + k + "=" + v + "':", count)

Output

Occurrences of 'name=harry': 3

Explanation:

  • for line in f: Reads the file line by line.
  • line.strip() == k + "=" + v: Checks if the cleaned line matches the target key–value pair.
  • count = count + 1: Increments the count when a match is found.

Using Regular Expressions

This method uses the re module to find all exact matches of the key-value pair in the file.

Python 
import re

k = "name"
v = "Harry"

with open("file.txt", "r") as f:
    data = f.read()

pattern = r"\b" + re.escape(k) + "=" + re.escape(v) + r"\b"
matches = re.findall(pattern, data)

print("Occurrences of '" + k + "=" + v + "':", len(matches))

Output

Occurrences of 'name=Harry': 3

Explanation:

  • f.read(): Reads the whole file as a single string.
  • re.escape(k) / re.escape(v): Ensures special characters are treated literally.
  • pattern = r"\b" + re.escape(k) + "=" + re.escape(v) + r"\b": Builds a regex to match the exact key–value pair.
  • re.findall(pattern, data): Finds all matches; len(matches) gives the total count.

Using readlines() + Loop

This method reads all lines of the file into a list and then loops through them to count the key-value pair. It’s simple but not memory-efficient for large files.

Python 
k = "name"
v = "Harry"
count = 0

with open("file.txt", "r") as f:
    lines = f.readlines()

for line in lines:
    if line.strip() == k + "=" + v:
        count = count + 1

print("Occurrences of '" + k + "=" + v + "':", count)

Output

Occurrences of 'name=Harry': 3

Explanation:

  • f.readlines(): Reads all lines into a list.
  • Loop checks each line for the target key-value pair and increments count.
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