Count Substring Occurrences¶

Count the number of times a substring appears in a string using the standard library.

6 snippets available in this sub-category.

Simple¶

Count substring occurrences¶

string count substring occurrences text

Count occurrences of a substring in a string

def count_substring(text, substring):
    """Count occurrences of substring in text."""
    return text.count(substring)


text = "hello world hello python hello"
count = count_substring(text, "hello")
print(count)  # 3

Notes

Uses str.count() method
Case-sensitive matching
Returns integer count
Simple and efficient

Count with case-insensitive matching¶

string count substring case-insensitive text

Count substring occurrences ignoring case differences

def count_substring_ignore_case(text, substring):
    """Count substring occurrences ignoring case."""
    return text.lower().count(substring.lower())


text = "Hello World HELLO Python hello"
count = count_substring_ignore_case(text, "hello")
print(count)  # 3

Notes

Converts both strings to lowercase
Handles mixed case text
Useful for user input matching
Maintains original text

Complex¶

Count overlapping substrings¶

string count substring overlapping find text

Count overlapping substring occurrences

def count_overlapping_substrings(text, substring):
    """Count overlapping substring occurrences."""
    count = 0
    start = 0
    while True:
        pos = text.find(substring, start)
        if pos == -1:
            break
        count += 1
        start = pos + 1
    return count


text = "aaaa"
count = count_overlapping_substrings(text, "aa")
print(count)  # 3 (positions: 0, 1, 2)

Notes

Handles overlapping matches
Uses str.find() with start position
More complex than str.count()
Useful for pattern analysis

Count with word boundaries¶

string count word boundaries regex text

Count word occurrences with proper boundaries

import re


def count_word_occurrences(text, word):
    """Count word occurrences with word boundaries."""
    pattern = r"\b" + re.escape(word) + r"\b"
    matches = re.findall(pattern, text)
    return len(matches)


text = "hello world hello python hello-world"
count = count_word_occurrences(text, "hello")
print(count)  # 2 (excludes "hello-world")

Notes

Uses regex word boundaries
Excludes partial matches
Handles punctuation
More precise than simple count

Count multiple substrings¶

string count multiple substrings dictionary text

Count occurrences of multiple substrings at once

def count_multiple_substrings(text, substrings):
    """Count occurrences of multiple substrings."""
    results = {}
    for substring in substrings:
        results[substring] = text.count(substring)
    return results


text = "hello world hello python world"
substrings = ["hello", "world", "python"]
counts = count_multiple_substrings(text, substrings)
print(counts)  # {'hello': 2, 'world': 2, 'python': 1}

Notes

Returns dictionary of counts
Efficient for multiple searches
Useful for text analysis
Batch processing approach

Count with position tracking¶

string count substring positions tracking text

Count substring and track all occurrence positions

def count_substring_positions(text, substring):
    """Count substring and return all positions."""
    positions = []
    start = 0
    while True:
        pos = text.find(substring, start)
        if pos == -1:
            break
        positions.append(pos)
        start = pos + 1
    return len(positions), positions


text = "hello world hello python hello"
count, positions = count_substring_positions(text, "hello")
print(f"Count: {count}, Positions: {positions}")
# Count: 3, Positions: [0, 12, 24]

Notes

Returns both count and positions
Useful for text processing
Enables position-based operations
Combines counting and finding

🔗 Cross-References¶

Reference: See 📂 Find String
Reference: See 📂 Is Anagram

🏷️ Tags¶

string, count, substring, find, frequency, text

📝 Notes¶

Use str.count() for non-overlapping substring counts
Use regex for overlapping or complex patterns
Useful for text analysis and validation