count(): Number of presence of a string

my_str="Welcome to plus2net.com"
print(my_str.count('co'))      # Output is 2
print(my_str.count('co',4))    # Output is 1 
print(my_str.count('co',4,18)) # Output is 0
print(my_str.count('o',4,9))   # Output is 1
print(my_str.count('o',4,10))  # Output is 2

my_str.count(search_string,start,end))

my_list=['one','two','three']
print(my_list.count('two'))      # Output is 1

Example: Counting Substrings Across Multiple Lines

We can use `count()` to identify substrings across multiple lines. This is particularly useful when processing multi-line text files or user inputs.

text = """Welcome to plus2net.com
Visit us for Python tutorials.
Enjoy your learning journey at plus2net.com!"""
count = text.count("plus2net.com")
print(count)

2

Use Case: Case-Insensitive Count with Regular Expressions

To perform a case-insensitive count, we can use the `re` module instead of `count()`. This is helpful when the exact match case isn't important.

import re
text = "Python is fun. PYTHON is versatile. python is popular."
count = len(re.findall(r'python', text, re.IGNORECASE))
print(count)

3

Advanced Example: Counting Words in a File

Regular use of `count()` can help in text analysis, such as determining word frequencies in a file.

file_name = 'example.txt'
with open(file_name, 'r') as file:
    content = file.read()
    word_count = content.count("Python")
print(f"'Python' appears {word_count} times in the file.")

'Python' appears 5 times in the file.

Example: Counting Character Sequences with Optional Start and End

We can specify start and end parameters to limit the search to specific sections of a string, which helps when analyzing parts of data.

my_str = "Find your way in Python programming"
print(my_str.count("y", 5, 20))

3

Subhendu Mohapatra

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