Python String Methods

January 17, 2020 . Python

In this article, you will learn how to use some built-in methods for Python. Strings in python are surrounded by either single or double quotation marks and each character in a string is assigned an index.

Section Overview

• count()
• center()
• swapcase()
• find()
• split()
• startswith()
• endswith()
• ljust() and rjust()
• string capitalization
• zfill()
• strip()

Let’s look at string methods:

Section 1. count()

The count() method returns the number of occurrences of a substring in the given string.

Syntax:

string.count(substring, start, end)

Parameters:

• substring (Required) is the string whose count is to be found.
• start (Optional) is the starting index for the string.
• end (Optional) is the ending index for the string.

Let’s look at the example without optional parameters:

Let’s look at the example using optional parameters:

Section 2. center()

The center() method creates and returns a new string. Whitespace is the default.

Syntax:

string.center(length, fillchar)

Parameters:

• length (Required) is the length of the string.
• fillchar (Optional) is the character which needs to be padded.

Let’s look at the example without optional parameters:

Let’s look at the example using optional parameters:

Section 3. swapcase()

The swapcase() method converts all uppercase characters to lowercase or all lowercase characters to uppercase.

Syntax:

string.swapcase()

Let’s look at the example:

Section 4. find()

The find() method returns the lowest index in the string where substring sub is found within the slice s[start:end].

Syntax:

string.find(substring, start, end)

Parameters:

• substring (Required) which is to be searched in the given string.
• start (Optional) is the starting position where substring is to be checked within the string.
• end (Optional) is the ending position where substring is to be checked within the string.

Let’s look at the example without optional parameters:

Let’s look at the example using optional parameters:

Section 5. split()

The split() method returns a list of strings in a string for breaking the given string by the specified separator. Also, default separator is any whitespace.

Syntax:

string.split(separator, maxsplit)

Parameters:

• separator (Optional) is delimiter. The string splits at this specified separator. Default separator is any whitespace.
• maxsplit (Optional) is a number of splits. If it is not used than there is not limit.

Note: You can use rsplit() for splits a string from the right.

Let’s look at the example:

Section 6. startswith()

The startswith() method return True, if starting with the given specified value in a string. Otherwise, it return False.

Syntax:

string.startswith(search_string, start, end)

Parameters:

• search_string (Required) is the string to be searched.
• start (Optional) is the starting position where substring is to be checked within the string.
• end (Optional) is the ending position where substring is to be checked within the string.

Let’s look at the example without optional parameters:

Let’s look at the example using optional parameters:

Section 7. endswith()

The endswith() method return True, if ending with the given specified value in a string. Otherwise, it return False.

Syntax:

string.endwith(search_string, start, end)

Parameters:

• search_string (Required) is the string to be searched.
• start (Optional) is the starting position where substring is to be checked within the string.
• end (Optional) is the ending position where substring is to be checked within the string.

Let’s look at the example without optional parameters:

Let’s look at the example using optional parameters:

Section 8. ljust() and rjust()

The ljust and rjust will left or right align the string, using a specified character (space is default) as the fill character.

Syntax:

string.ljust(s, fillchar)
string.rjust(s, fillchar)

Parameters:

• length (Required) is the width of string to expand it.
• fillchar (Optional) is the character to fill in remaining space.

Let’s look at the example:

Section 9. String Capitalization

Section 9.1. capitalize()

The capitalize() method converts only the first character of a string to capital (uppercase) letter.

Syntax:

string.capitalize()

Let’s look at the example:

Section 9.2. upper()

The upper() method converts all characters of the a string to uppercase letter.

Syntax:

string.upper()

Let’s look at the example:

Section 9.3. title()

The title() method converts all the first character of the a string to uppercase letter.

Syntax:

string.title()

Let’s look at the example:

Section 10. zfill()

The zfill() method returns a copy of the string with 0 characters padded to the leftside of the given string.

Syntax:

string.zfill(length)

Parameters:

• length is the length of the returned string from zfill() with 0 digits filled to the leftside.

Let’s look at the example:

Section 11. strip()

The strip() method returns a copy of the string with both leading and trailing characters removed.

• rstrip(): strips characters from the right in a string.
• lstrip(): strips characters from the left in a string.

Syntax:

string.strip(character)

Parameters:

• character (Optional): set of characters to be removed.

Let’s look at the example:

Conclusion

In this article you’ve learned how to use some built-in methods for Python. You can visit Python documentation for learning deeper.

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