Python count() function for strings
In this article, you will learn how to use the in-built count() function for strings to count the number of
non-overlapping occurrences of characters or substrings in a given input string.
Syntax:
count(substring, start, end)
substring: characters or substring to search within a given string. It is required.
start : position to start a search within a string (default is 0). It is optional.
end : position to end search within a string (default is string end). It is optional.
It returns an integer value of count
count() function is case-sensitive, and hence the count of “A” or “a” is not the same
Let’s see some examples of count() function
1. Count the number of occurrences of characters
# create any random string
dna = "ATGGTATTAATTATCTGAta"
In this string, count the number of occurrences of T character
dna.count("T")
# output
8
2. Count the number of occurrences of substring
Count the number of occurrences of TA substring
dna.count("TA")
# output
3
3. Count the number of occurrences of substring using start and end positions
Count the number of occurrences of TA substring starting from 6th position to end position
# in Python, index starts at 0
dna.count("TA", 5)
# output
2
Count the number of occurrences of TA substring starting from 6th position to 10th position
# in Python, index starts at 0
dna.count("TA", 5, 9)
# output
1
4. count() function is case-sensitive
Count the number of occurrences of ta substring
dna.count("ta")
# output
1
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