Last Updated on June 19, 2023 by Mayank Dham
Python, as a versatile and powerful programming language, offers a wide range of built-in methods and functions to manipulate and work with strings. Strings are fundamental data types in Python, representing sequences of characters enclosed in single quotes (”) or double quotes (""). Python provides an extensive set of string methods and functions that allow developers to perform various operations, such as searching, modifying, formatting, and analyzing strings.
What is Python String?
In Python, a string is a sequence of characters enclosed within single quotes (”), double quotes (" "), or triple quotes (""" """). It is a fundamental data type used to represent and manipulate textual data. Strings in Python are immutable, which means that once a string is created, it cannot be modified. However, you can perform various operations on strings to extract information, manipulate their content, and create new strings.
Strings in Python are versatile and support a wide range of operations and methods. They can be concatenated (joined together), sliced (extracted portions), iterated over character by character, and formatted to display variables or other data dynamically. Python provides a rich set of built-in methods and functions to work with strings, making it easy to perform operations like searching for substrings, replacing characters, converting case, and much more.
Strings can contain alphanumeric characters, special characters, whitespace, and even escape sequences (such as newline or tab). They can represent plain text, numbers, URLs, file paths, JSON data, and virtually any textual information. Python treats strings as a sequence of individual characters, allowing you to access specific characters or subsets of characters using indexing and slicing.
Take into account the Python example below to generate a string.
Syntax of Python String:
str = "Hi Python !"Here, if we use a Python script to determine the type of the variable str
print(type(str)), then it will print a string (str).Because strings are seen as collections of characters, Python does not allow the character data-type; instead, a single character written as "p" is interpreted as a string of length 1.
Creating String in Python
We can make the characters into a string by enclosing them in single or double quotation marks. Python also supports triple-quotes to signify the text, albeit they are more frequently used for multiline texts or docstrings.
#Using single quotes
str1 = 'Hello Python'
print(str1)
#Using double quotes
str2 = "Hello Python"
print(str2)
#Using triple quotes
str3 = '''''Triple quotes are generally used for
represent the multiline or
docstring'''
print(str3) Strings Indexing and Splitting
As shown in the Python example, the slice operator [] is used to access the string’s individual characters. However, we may use Python’s: (colon) operator to extract the substring from the given text. Think about the scenario below.
Consider the following example:
str = "HELLO"
print(str[0])
print(str[1])
print(str[2])
print(str[3])
print(str[4])
# It returns the IndexError because 6th index doesn't exist
print(str[6]) The slice operator [] is used to access the string’s individual characters, as demonstrated in Python. However, we may obtain the substring from the provided text in Python by using the: (colon) operator. Consider the case below.
In this case, it’s important to note that the higher range specified by the slice operator is always exclusive; for example, if str = ‘HELLO’ is supplied, str[1:3] will always include str[1] = ‘E’ and str[2] = ‘L’ and nothing else.
Python String Methods
Python has 47 methods for handling strings. There are almost as many built-in Python functions as there are string methods. Which string operations ought you learn first?
There are about a dozen string techniques that are quite beneficial and should be memorized. We’ll quickly review the other approaches and the reasons they’re less successful after looking at the most beneficial string ways.
Table of Python String Methods
| Function Name | Description |
|---|---|
| capitalize() | the string’s initial character is changed to an uppercase (capital) letter. |
| casefold() | uses case-free string matching |
| center() | Add the requested character to the string as padding. |
| count() | The number of times a substring appears in the string is returned. |
| encode() | Strings are encoded using the chosen encoding technique. |
| endswith() | If a string ends with the specified suffix, it returns "True." |
| expandtabs() | specifies how much space will be used to replace the string’s "t" symbol. |
| find() | if the substring is discovered, returns the lowest index of the substring. |
| format() | prepares the string for console output. |
| format_map() | uses a dictionary to format given values in a string. |
| index() | returns the location of a substring’s first occurrence within a string. |
| isalnum() | determines if every character in a string is an alphabetic character. |
| isalpha() | returns "True" if the string contains just alphabetic letters. |
| isdecimal() | returns true if a string contains only decimal characters. |
| isdigit() | returns "True" if the string contains just numbers. |
| isidentifier() | Verify whether a string is a recognized identifier. |
| islower() | determines if all of the string’s characters are lowercase. |
| isnumeric() | returns "True" if the string contains just numeric characters. |
| isprintable() | Returns "True" if the string contains just readable characters or nothing at all. |
| isspace() | returns "True" if the string only contains whitespace characters. |
| istitle() | If the string is a title-cased string, it returns "True." |
| isupper() | determines if every character in the string is capitalised |
| join() | produces a String that has been joined. |
| ljust() | Left aligns the string according to the width specified |
| lower() | Converts all uppercase characters in a string into lowercase |
| lstrip() | Returns the string with leading characters removed |
| maketrans() | Returns a translation table |
| partition() | Splits the string at the first occurrence of the separator |
| replace() | Replaces all occurrences of a substring with another substring |
| rfind() | Returns the highest index of the substring |
| rindex() | Returns the highest index of the substring inside the string |
| rjust() | Right aligns the string according to the width specified |
| rpartition() | Split the given string into three parts |
| rsplit() | Split the string from the right by the specified separator |
| rstrip() | Removes trailing characters |
| splitlines() | Split the lines at line boundaries |
| startswith() | Returns “True” if a string starts with the given prefix |
| strip() | Returns the string with both leading and trailing characters |
| swapcase() | Converts all uppercase characters to lowercase and vice versa |
| title() | Convert string to title case |
| translate() | Modify string according to given translation mappings |
| upper() | Converts all lowercase characters in a string into uppercase |
| zfill() | Returns a copy of the string with ‘0’ characters padded to the left side of the string |
Python has many built-in functions that can be used to change strings. Each of these routines returns a new string while preserving the integrity of the previous string because Python Strings are immutable.
Python String Functions
There are several ways to manipulate a String. It’s impossible to recall them all, though. So I’ve separated them into several categories here.
- Must Know String Functions
- Good to Know String Functions
- Miscellaneous String Functions
- Built-in Functions that work on String
- Useful String Operations
Must Know String Functions
| Function | Description |
|---|---|
| format() | It’s used to create a formatted string from the template string and the supplied values. |
| split() | Python string split() function is used to split a string into the list of strings based on a delimiter. |
| join() | This function returns a new string that is the concatenation of the strings in iterable with string object as a delimiter. |
| strip() | Used to trim whitespaces from the string object. |
| format_map() | Python string format_map() function returns a formatted version of the string using substitutions from the mapping provided. |
| upper() | We can convert a string to uppercase in Python using str.upper() function. |
| lower() | This function creates a new string in lowercase. |
| replace() | Python string replace() function is used to create a new string by replacing some parts of another string. |
| find() | Python String find() method is used to find the index of a substring in a string. |
| translate() | Python String translate() function returns a new string with each character in the string replaced using the given translation table. |
Good to Know String Functions
| Function | Description |
|---|---|
| encode() | Python string encode() function is used to encode the string using the provided encoding. |
| count() | Python String count() function returns the number of occurrences of a substring in the given string. |
| startswith() | Python string startswith() function returns True if the string starts with the given prefix, otherwise it returns False. |
| endswith() | Python string endswith() function returns True if the string ends with the given suffix, otherwise it returns False. |
| capitalize() | Python String capitalize() function returns the capitalized version of the string. |
| center() | Python string center() function returns a centered string of specified size. |
| casefold() | Python string casefold() function returns a casefolded copy of the string. This function is used to perform case-insensitive string comparison. |
| expandtabs() | Python string expandtabs() function returns a new string with tab characters (\t) replaced with one or more whitespaces. |
| index() | Python String index() function returns the lowest index where the specified substring is found. |
| contains() | Python String class has a __contains__() function that we can use to check if it contains another string or not. We can also use “in” operator to perform this check. |
Have I listed All the Python String Methods?
Almost all of the important Python string functions have been covered. But some of them might have been overlooked. Python 3.7 is the most recent version of this list. Therefore, any feature that will be present in later editions is not yet present in this one. If there are any essential elements that I’ve overlooked, do let me know in the comments and I’ll add them as well.
Conclusion
Python string methods and functions provide a powerful and convenient way to manipulate and process strings in Python. They offer a wide range of operations, such as searching, modifying, formatting, and analyzing strings, which can simplify string-related tasks and enhance your productivity as a developer. By leveraging these built-in capabilities, you can handle common string operations efficiently without the need for complex algorithms or external libraries.
Throughout this article, we explored various essential Python string methods and functions. We covered operations like concatenation, slicing, case conversion, searching, replacing, and formatting. We provided clear explanations and practical examples to demonstrate how these methods and functions can be used effectively.
By understanding and utilizing Python string methods and functions, you can streamline your string manipulation code, make it more readable, and reduce the likelihood of errors. Whether you are working on web development, data processing, text analysis, or any other Python project involving strings, having a solid grasp of these string manipulation tools is invaluable.
FAQs (Frequently Asked Questions):
Q1. What is the difference between a string method and a string function in Python?
String methods are specific to string objects and are called using dot notation (e.g., my_string.upper()), while string functions are built-in functions that operate on strings as arguments (e.g., len(my_string)).
Q2. Are Python strings mutable?
No, strings in Python are immutable, which means they cannot be modified once created. However, you can perform operations that return new modified strings.
Q3. How can I concatenate strings in Python?
You can concatenate strings using the + operator or by using the str.join() method.
Q4. How can I convert a string to uppercase or lowercase?
You can convert a string to uppercase using the upper() method or to lowercase using the lower() method.
Q5. How can I check if a substring exists within a string?
You can use the in operator or the str.find() or str.index() methods to check if a substring is present in a string.