Strings Methods In Python

Here we learn Python strings methods in the hope that it will meet your educational needs.

Python Strings Methods

There are a number of Python built-in methods that can be used to manipulate strings.

There is one thing to keep in mind when using string methods: they all return new values. In other words, they do not change the original string in any way.

Python Strings Methods List

It is imperative to note that Python strings methods return rewritten values. The original string remains unchanged.

Python Strings Tutorial explains strings in more detail.

Python Strings Methods Examples

The following is an in-depth explanation of Python Strings Methods, with examples for each method.

Python Strings Method capitalize()

Capitalize() method generates a string with the first character in upper case, and the remaining characters in lower case.

Syntax:

string.capitalize()

There are no parameters. The following sentence begins with an uppercase letter:

We convert the first character to uppercase, and the following characters to lowercase:

Try it with a number as the first character:

As a first character, test a symbol:

Python Strings Method casefold()

Python String Casefold() generates a string with all characters in lower case.

In comparison to lower(), casefold() is better, more efficient, indicating that it will transform more characters into lower case, and will find more matches when comparing two strings transformed by casefold().

Syntax:

string.casefold()

There are no parameters. Change the string to lower case:

Try it with a number as the first character:

Python Strings Method center()

Python String Center() method will position the string in the center, using a given character as fill (space by default).

Syntax:

string.center(length, character)

Parameter Values

In the center of the 70 characters, display the word “mrexamples”:

Utilizing the symbol “*” as the padding character:

First implement the casefold() method to string then apply the center() method:

Python Strings Method count()

The Count() method displays the occurrences of a given value present in the string.

Syntax:

string.count(value, start, end)

Parameter Values

Find out how many times the string contains the word “python“:

From position 15 to 154, find as follows:

First apply the capitalize() method to the string then utilize the count() method:

Python Strings Method encode()

The Encode() method encodes a string with the given encoding. In the absence of an encoding standard, UTF-8 will be utilized.

Syntax:

string.encode(encoding=encoding, errors=errors)

Parameter Values

Using UTF-8, encode the string as follows:

The following examples use ASCII encoding and a character that is unable to be encoded, displaying various errors:

Implement the center() method to the string then utilize the encode() method to display the various errors of the characters that are not able to encode.

Python Strings Method endswith()

When the string ends with the given value, the endswith() method provides True, else False.

Syntax:

string.endswith(value, start, end)

Parameter Values

If there is a punctuation mark (?) at the end of the string, verify it:

If the string ends with “method?” verify the following:

If position 0 to 14 ends with “Python strings methods?“, verify the following:

Encode the string message utilizing the encode() method then apply the endswith() method to verify the string ends with “python strings methods?”:

Python Strings Method expandtabs()

By calling the expandtabs() method, the tab size is set to the number of whitespaces given.

Syntax:

string.expandtabs(tabsize)

Parameter Values

To set the tab size to three blank spaces:

Apple the casefold() method and count() method then set the tab size to four blank spaces:

Utilizing various tab sizes, you can examine the results:

Python Strings Method find()

The find() method locates the initial appearance of the given value.

If the value cannot be located, find() method displays -1.

There is only one difference between the find() method and the index() method. If the value cannot be found, the index() method throws an error. (Refer to the below example)

Syntax

string.find(value, start, end)

Parameter Values

What is the location of the word “python” in the text? :

What is the first appearance of “r” in the text? :

If you only search between positions 20 and len(mrx), where is the first appearance of the character “r“? :

The find() method returns -1 if the value could not be located, but the index() method will throw an error:

Capitalize the string first, utilize the count() method to the capitalized string then apply the find() method:

Python Strings Method format()

The Format() method formats the given value(s) and adds them to the string’s placeholder.

Curly brackets are utilized to identify the placeholder: {}. In the Placeholder area below, you can learn a lot about placeholders.

The format() method provides a well-formatted string.

Syntax

string.format(value1, value2...)

Parameter Values

Place the net_worth in the placeholder, in three-digit fixed point form:

Placeholders

It is feasible to recognize the placeholders based on their names {net_worth}, numbers {0}, or possibly by empty placeholders {}.

Placing a variety of placeholder values:

Utilize the center() method to display the “Billionaires” string in the center and place a variety of placeholder values. In the last step, apply the capitalize(), casefold() and find() methods to the strings:

Formatting Types

Insert a formatting type within the placeholders to format the output:

Python Strings Method index()

By calling the index() method, you can locate the first appearance of a value you provide.

If the value cannot be located, index() throws an error.

The index() method is almost identical to the find() method, with the exception that the find() method provides -1 if no value is located. (Check out the example below)

Syntax

string.index(value, start, end)

Parameter Values

What is the location of the word “python” in the text? :

What is the first appearance of “r” in the text? :

If you only search between positions 20 and len(mrx), where is the first appearance of the character “r”? :

The find() method returns -1 if the value could not be located, but the index() method will throw an error:

Capitalize the string first, utilize the count() method to the capitalized string then apply the index() method:

Python Strings Method isalnum()

When all the characters are letters (a-z) and digits (0-9), then the isalnum() method produces True.

Non-alphanumeric characters: (space)!#%&? etc.

Syntax

string.isalnum()

Parameters are not required – Make sure each of the characters in the string is alphanumeric:

Verify that each of the characters in the string is alphanumeric:

Apply the underscore to the alphanumeric string:

Python Strings Method isascii()

If each of the characters are ASCII characters, the isascii() method displays True.

Syntax

string.isascii()

Parameters are not required – Make sure each of the characters in the string is ASCII:

Verify that each character in the mrx string is ASCII:

Python Strings Method isdecimal()

If each of the characters is a decimal (0-9), the isdecimal() method outputs True.

Unicode objects utilize this method.

Syntax

string.isdecimal()

Parameters are not required – Verify that all the characters in the Unicode object are decimal:

Make sure that each of the characters in Unicode are decimals:

Ensure that each Unicode character is a decimal:

Python Strings Method isdigit()

If each and every character is digits, the isdigit() method provides True, else False.

Numbers with exponents, such as ², are also regarded as digits.

Syntax

string.isdigit()

Parameters are not required – Verify that all of the string characters are numbers:

First, separate the thousand by an underscore, then verify that all string characters are digits:

Prove that all of the string characters are numbers:

Python Strings Method isidentifier()

If the string is a correct identifier, isidentifier() provides True, else False.

Strings with only alphanumeric characters (a-z) and zero through nine, or underscores (_), are accepted as correct identifiers.

A correct identifier cannot begin with a number or include any spaces.

Syntax

string.isidentifier()

Parameters are not required – Verify that the string is a correct identifier:

Make sure the string is the correct identifier:

To find out if the strings are correct identifiers, check the following:

Python Strings Method islower()

If all the letters are in small case, the islower() method outputs True, else outputs False.

Only alphabetic characters are validated, not numbers, symbols, or spaces.

Syntax

string.islower()

There are no parameters – Make sure all the letters in the string are lowercase:

If the first character in a string is a digit, ensure that all the characters are in lower case:

Verify that all the letters in the multiple strings are in smaller case:

Python Strings Method isnumeric()

When all characters (0-9 are numeric), isnumeric() provides True, else it gives False.

Numerical values include exponents, such as ⁷ and ¾.

“-7” and “4.5” are unable to be accepted as numeric values, because every characters in the string have to be numeric, and the – and “.” are not.

Syntax

string.isnumeric()

Parameters are not required – Verify that all of the string characters are numeric:

First, separate the thousand by a comma in the string, then verify that all string characters are numeric:

Make sure the characters are in numeric form:

Python Strings Method isprintable()

Isprintable() returns True if all characters are printable, otherwise False.

In addition to carriage returns and line breaks, there are several non-printable characters.

Syntax

string.isprintable()

Parameters are not required – Verify that all of the string characters are printable:

Make sure the string is printable by checking the following:

Ensure that all the characters in the string are printable:

Python Strings Method isspace()

If all the characters in a string are empty spaces, the isspace() method returns True, while it returns False.

Syntax

string.isspace()

Parameters are not required – Make sure all the characters in the string are empty spaces:

Verify that all the characters in the string are blank spaces:

Find out that all the characters in the string are empty spaces:

Python Strings Method istitle()

When all words in a text have an uppercase letter and the remainder are lowercase letters, the istitle() method provides True; else, it provides False.

It is not necessary to include symbols or numbers.

Syntax

string.istitle()

Parameters are not required – Make sure every word begins with an uppercase letter:

Verify that every word begins with an uppercase letter in the following example:

In the following example, ensure that each word in the string begins with an uppercase letter:

Python Strings Method isupper()

If all the letters are in larger case, the isupper() method outputs True, else outputs False.

Only alphabetic characters are validated, not numbers, symbols, or spaces.

Syntax

string.isupper()

There are no parameters – Make sure all the letters in the string are uppercase:

If the first character in a string is a digit, ensure that all the characters are in upper case:

Verify that all the letters in the multiple strings are in larger case:

Python Strings Method join()

In the join() method, each of the elements in an iterable is joined into a single string.

As a separator, you have to provide a string.

Syntax

string.join(iterable)

Parameter Values

By applying a ” –> ” as a separator, join all elements in a tuple into a string:

Utilize a “\n” as a separator, join all elements in a tuple into a string:

Create a string by connecting all entries in a dictionary with the word “TRY” as a separating word:

Reminder: As an iterable, a dictionary displays the keys, not the values.

Python Strings Method ljust()

By calling the ljust() method, a chosen character (space by default) will be assigned as the fill character of the string.

Syntax

string.ljust(length, character)

Parameter Values

By applying a ” –> ” as a separator, join all elements in a tuple into a string:

Utilize a “\n” as a separator, join all elements in a tuple into a string:

Create a string by connecting all entries in a dictionary with the word “TRY” as a separating word:

Python Strings Method lower()

lower() method generates a string that contains all letters in small case.

Numbers and symbols are not taken into account.

Syntax

string.lower()

There are no parameters – Make the string smaller case:

Apply the digits at the beginning of the string then convert the string to small case:

Python Strings Method lstrip()

lstrip() eliminates any preceding characters (the space character is the default preceding character).

Syntax

string.ljust(length, character)

Parameter Values

Left-justify the string by eliminating spaces:

Pass the value “>” in the lstrip() method:

Take out the preceding characters:

Python Strings Method maketrans()

Maketrans() method provides a mapping table that can be utilized with the translate() method to substitute selected characters.

Syntax

string.maketrans(x, y, z)

Parameter Values

Utilize the mapping table in the translate() method to substitute any “G” characters for “H” characters:

Initially implement the lower() method on string, then apply the maketrans() method:

To substitute multiple characters, utilize a mapping table:

You can delete characters from the string through the third parameter in the mapping table:

In Unicode, the maketrans() method generates a dictionary explaining each substitution:

Python Strings Method partition()

Through the partition() method, you can look for a string and divide it into tuples with three elements.

In the first element, the part preceding the given string is included.

The string mentioned in the second element can be found in the second element.

After the string, the third element includes the part.

Reminder: This method finds the initial appearance of the given string.

Syntax

string.partition(value)

Parameter Values

Provide a tuple with three elements that include the word “partition()“:

1. Anything that precedes “equivalent”
2. The “equivalent”
3. Anything that follows “equivalent”

Apply the title() method to the mrx string, then utilize the partition() method:

Partition() method generates a tuple with: first the whole string, second an unfilled string, third an unfilled string if the given value is not present:

Python Strings Method replace()

By calling the replace() method, you can substitute a phrase for a new phrase.

Reminder: A substitution will be executed on all occurrences of the given phrase if nothing else is provided.

Syntax

string.replace(oldvalue, newvalue, count)

Parameter Values

Substitute “3.8.0” to “3.11.1”:

Utilize the replace() method on a string, then implement the partition() method:

Change all appearances of “two” to “nine”:

Change the first appearance of the word “two” to “nine”:

Python Strings Method rfind()

rfind() method locates the last appearance of a value.

A value cannot be located if the rfind() method returns -1.

The rfind() method is nearly identical to the rindex() method. You can see an example below.

Syntax

string.rfind(value, start, end)

Parameter Values

In what part of the text does the string “language” occur at the end? :

Utilize the count() method on a string, then apply the rfind() method:

In the string where is the last appearance of the character “o”? :

When you only find between positions 0 and 36, where is the final appearance of the character “t”? :

The rfind() method provides -1 if the value cannot be located, but the rindex() method throws an error if the value cannot be found:

Python Strings Method rindex()

The rindex() method searches for the last instance of a given value.

If the value is not found, an error will occur.

It is essentially identical to the rfind() method- please refer to the example for more information.

Syntax

string.rindex(value, start, end)

Parameter Values

In what part of the text does the string “language” occur at the end? :

Utilize the count() method on a string, then apply the rindex() method:

In the string where is the last appearance of the character “o”? :

When you only find between positions 0 and 36, where is the final appearance of the character “t”? :

The rfind() method provides -1 if the value cannot be located, but the rindex() method throws an error if the value cannot be found:

Python Strings Method rjust()

The rjust() method aligns text to the right side of a string, utilizing either a space or a given character as padding.

Syntax

string.rjust(length, character)

Parameter Values

Provide a right-aligned 35-character representation of “Python”:

As a padding character, utilize the symbol “*”:

For a padding character, apply the symbols “>” and “<“:

Python Strings Method rpartition()

The rpartition() method looks for the final instance of a given string, which it then divides into a tuple of three elements: The part before the string, the string itself, and the part after it.

Syntax

string.rpartition(value)

Parameter Values

Provide a tuple with three elements that include the word “rpartition()“:

1 – Anything that precedes “equivalent”
2 – the “equivalent”
3 – Anything that follows “equivalent”

Apply the title() method to the mrx string, then utilize the rpartition() method:

The rpartition() method generates a tuple with: first an unfilled string, second an unfilled string if the given value is not present, third the whole string:

Python Strings Method rsplit()

The rsplit() method will separate a string into a list beginning from the right, unless the “max” parameter is set. It results in the same outcome as the split() function.

Reminder: When maxsplit is given, the resulting list can include up to that many elements plus one.

Syntax

string.rsplit(separator, maxsplit)

Parameter Values

Divide a string into a list by utilizing a comma and a space (“, “) as the delimiter.

Apply the rsplit() method to the mrx string, then utilize the join() method:

Divide the string into a list of at most 4 items:

Python Strings Method rstrip()

With the rstrip() method, you can eliminate trailing characters (the last characters in a string).

By default, the following character is a space.

Syntax

string.rstrip(characters)

Parameter Values

At the last of the string, delete any empty spaces:

Pass the value “*” in the rstrip() method:

Take out the following characters:

Python Strings Method split()

Strings can be divided into lists utilizing the split() method.

Default separator is any empty space, but you can choose it.

Reminder: Selecting maxsplit will result in a list with the given number of elements plus one.

Syntax

string.split(separator, maxsplit)

Parameter Values

Make a list from a string, with each word appearing as an item:

Divide a string into a list by utilizing a comma and a space (“, “) as the delimiter.

Apply the split() method to the mrx string, then utilize the join() method:

In place of a separator, utilize the dollar “$” character:

Divide the string into a list of at most 4 items:

Python Strings Method splitlines()

A string is divided into a list utilizing the splitlines() method. Line breaks are used to divide the text.

Syntax

string.splitlines(keeplinebreaks)

Parameter Values

Divide a string into a list with each line representing an item:

Make a list where each line is a list element from a string:

Maintain the line breaks when dividing the string:

Python Strings Method startswith()

If the string begins with the given value, the startswith() method provides True, else False.

Syntax

string.startswith(value, start, end)

Parameter Values

Make sure the string begins with “Greetings”:

Verify that the string begins with “Greetings”:

Make sure position 18 to 40 begins with “lear”:

Python Strings Method strip()

The strip() method eliminates preceding (spaces at the beginning) and following (spaces at the last) characters (by default, a space is the leading character).

Syntax

string.strip(characters)

Parameter Values

Take out the spaces at the start and at the tail of the string:

Pass the value “*” in the rstrip() method:

Take out the preceding and following characters:

Python Strings Method swapcase()

By calling the swapcase() method, you can get a string that includes all uppercase letters transformed into lowercase letters, and the reverse.

Syntax

string.swapcase()

Parameters not required – Change the small case letters to capital case and the capital case letters to small case:

Apply the non-alphabetic characters:

Python Strings Method title()

The title() method generates a string with the first character in every word uppercase. It’s like a header or a title.

Words including numbers or symbols will be transformed into uppercase after the first letter.

Syntax

string.title()

Parameters are not required – Make sure every word begins with an uppercase letter:

Verify that every word begins with an uppercase letter in the following example:

Ensure that the initial letter of each word is uppercase:

In the following example, check that the initial letter after a non-alphabet letter is changed to uppercase:

Python Strings Method translate()

Translate() generates a string having some chosen characters substituted with the character stored in a dictionary or mapping table.

To make a mapping table, call the maketrans() method.

In the absence of a dictionary/table, a character will not be substituted.

In place of characters, you must utilize ASCII codes when referring to a dictionary.

Syntax

string.translate(table)

Parameter Values

If there is a “K” letter, substitute it with a “J” letter:

Substitute “K” with “J” through a mapping table:

To substitute multiple characters, utilize a mapping table:

You can delete characters from the string through the third parameter in the mapping table:

Utilizing a dictionary rather than a mapping table, here is the same example as above:

Python Strings Method upper()

upper() method generates a string that contains all letters in capital case.

Numbers and symbols are not taken into account.

Syntax

string.upper()

There are no parameters – Make the string larger case:

Apply the digits at the beginning of the string then convert the string to capital case:

Python Strings Method zfill()

The zfill() method inserts zeros (0) at the start of a string until it reaches the given length.

There is no filling if len is smaller than the length of the string.

Syntax

string.zfill(len)

Parameter Values

To make the string 6 characters wide, fill it with zeros:

Implement the zfill() method to string then utilize upper() method:

To make the strings various characters wide, fill them with zeros:

Having learned about Python strings methods and how they work, you are now prepared to use them.

Strings Methods In Python

The built-in string methods in Python are very important for working with and manipulating strings. Here are some reasons why:

1. The various string methods in Python allow you to manipulate and transform strings easily. You can convert strings to uppercase or lowercase, remove or add whitespace, split or join strings, and replace substrings with other substrings. These methods make it easy to manipulate strings for a wide range of use cases.
2. String methods can be used for data validation and cleaning, which is important for ensuring data quality. For example, you can use the isdigit() method to check if a string contains only digits, or the replace() method to remove unwanted characters from a string.
3. String methods are essential for text processing tasks, such as parsing and extracting data from text files or web pages. You can use methods like split() to extract individual words or substrings from a larger string, or the find() method to locate specific text within a larger document.
4. Python string methods work in conjunction with regular expressions, which are a powerful tool for pattern matching and text processing. Regular expressions allow you to search for and manipulate text based on complex patterns, and string methods like replace() and split() can be used in conjunction with regular expressions to achieve more advanced text processing tasks.
5. The built-in string methods in Python are highly optimized and performant, making them an efficient option for working with large strings or performing frequent string operations. Using the built-in methods also ensures that your code is compatible with different Python versions and environments.