Python String : The Ultimate Guide For Beginners 2021

Python String

String In Python – Single quote marks or double quotation marks are used to surround strings in Python. Strings are arrays of bytes in Python that represent Unicode characters. However, because Python lacks a character data type, a single character is merely a one-length string. Square brackets can be used to access the string’s elements.

Creating a String In Python

You can display a string literal with print() function:

Example Code:

  • Creating a String With Double Quotes

The code given above will display the string function using double quotes

Output:

Hello IT SOURCECODERS

  • Creating a String With Single Quotes

The code given above will display the string function using single quotes

Output:

Hello IT SOURCECODERS

Python String Split

Split a string into a list where each words is a list item:

Example Code:

The code given above will display the split string function using split() method

Output:

[‘Welcome’, ‘To’, ‘IT’, ‘SOURCECODE’]

Python String %s or Python String %

The %s operator is put where the string is to be specified. The number of values you want to append to a string should be equivalent to the number specified in parentheses after the % operator at the end of the string value.

Example Code:

The code given above illustrates the way of performing string formatting

Output:

Hello, IT SOURCECODE!

Python String Format or Python String Formatting

The format() method formats the specified values and insert them inside the sting’s placeholder.

Example Code:

Insert the price inside the placeholder, the price should be in fixed point, two-decimal format

Output:

For only 50.00 pesos!

Python String In String

Strings are arrays of bytes in Python that represent Unicode characters.

Example Code:

The code given above which is the String In String Python

Output:

My Name is: Angel Jude Suarez

Python String Replace or Python String Remove

The replace() function in Python returns a copy of the string with all occurrences of old replaced with new, with the number of replacements limited to max.

Example Code:

The replace() method replaces a specified phrase with another specified phrase.

Output:

I like Python

Python String Contains

The String._contains_() method check if one string contains another string.

Example Code:

This function will take two strings, and return if one string belongs to another. The return type of this method is therefore a boolean, so it will return either a True, or a False.

Output:

String contains target!

Python String Concatenation or Python String Concat

String Concatenation in Python means add string together.

Use the “+” character to add a variable to another variable.

Example Code:

The code given above will display the concatenation of two variable.

Output:

Python is Great

Python String Compare or Python String Comparison

Python String Equality (==) and comparison (, >,!=, =, >=) operators can be used to compare strings in Python. To compare two strings, there are no special methods.

Example Code:

The code given above is the python string comparison performed using the characters in both strings.

Output:

True
False
False
False
True
True

Python String List

String List In Python are used to store multiple items in a single variable.

Example Code:

The code given above is the python string list that created using square brackets

Output:

[‘apple’, ‘banana’, ‘cherry’]

Python String Reverse

The Python String Reverse library does not have an in-built “reverse()” function like other Python containers like list, knowing additional techniques to reverse a string can be useful.

Example Code:

We call a function to reverse a string in the above code, which iterates through each element and smartly joins each character in the beginning to produce the reversed string.

Output:

dlroW olleH

Python String Methods

Python provides a number of built-in techniques for working with strings.

MethodDescription
capitalize()Converts the first character to upper case
casefold()Converts string into lower case
center()Returns a centered string
count()Returns the number of times a specified value occurs in a string
encode()Returns an encoded version of the string
endswith()Returns true if the string ends with the specified value
expandtabs()Sets the tab size of the string
find()Searches the string for a specified value and returns the position of where it was found
format()Formats specified values in a string
format_map()Formats specified values in a string
index()Searches the string for a specified value and returns the position of where it was found
isalnum()Returns True if all characters in the string are alphanumeric
isalpha()Returns True if all characters in the string are in the alphabet
isascii()Returns True if all characters in the string are ascii characters
isdecimal()Returns True if all characters in the string are decimals
isdigit()Returns True if all characters in the string are digits
isidentifier()Returns True if the string is an identifier
islower()Returns True if all characters in the string are lower case
isnumeric()Returns True if all characters in the string are numeric
isprintable()Returns True if all characters in the string are printable
isspace()Returns True if all characters in the string are whitespaces
istitle()Returns True if the string follows the rules of a title
isupper()Returns True if all characters in the string are upper case
join()Converts the elements of an iterable into a string
ljust()Returns a left justified version of the string
lower()Converts a string into lower case
lstrip()Returns a left trim version of the string
maketrans()Returns a translation table to be used in translations
partition()Returns a tuple where the string is parted into three parts
replace()Returns a string where a specified value is replaced with a specified value
rfind()Searches the string for a specified value and returns the last position of where it was found
rindex()Searches the string for a specified value and returns the last position of where it was found
rjust()Returns a right justified version of the string
rpartition()Returns a tuple where the string is parted into three parts
rsplit()Splits the string at the specified separator, and returns a list
rstrip()Returns a right trim version of the string
split()Splits the string at the specified separator, and returns a list
splitlines()Splits the string at line breaks and returns a list
startswith()Returns true if the string starts with the specified value
strip()Returns a trimmed version of the string
swapcase()Swaps cases, lower case becomes upper case and vice versa
title()Converts the first character of each word to upper case
translate()Returns a translated string
upper()Converts a string into upper case
zfill()Fills the string with a specified number of 0 values at the beginning

Python String Length

Python len() function returns the length of the string.

Example Code:

The code given above is the  Len() function with tuples, list, and string.

Output:

12
3
4

Python String To Int

The built-in int() method in Python can be used to convert texts to integers. Any python data type can be sent to the int() method, which converts it to an integer. However, using the int() function isn’t the only option. Because a float value can be used to compute with integers, this type of conversion can also be done with thefloat() keyword.

Example Code:

The code given above is the list of possible ways to convert an integer to string in python.

Output:

<class ‘str’>

Python String Append

The string object in Python is immutable. As a result, whenever we use the + operator to concatenate two strings, we get a new string.

Example Code:

The code given above show on how to display Python String append.

Output:

Append using + operator: Hello IT SOURCECODEHello IT SOURCECODEHello IT SOURCECODEHello IT SOURCECODEHello IT SOURCECODE
Append using list and join(): Hello IT SOURCECODEHello IT SOURCECODEHello IT SOURCECODEHello IT SOURCECODEHello IT SOURCECODE
Append using * operator: Hello IT SOURCECODEHello IT SOURCECODEHello IT SOURCECODEHello IT SOURCECODEHello IT SOURCECODE

Python String Find

The find() method locates the first instance of a given value.

If the value cannot be retrieved, the find() function returns -1.

The only difference between the find() and index() methods is that the index() function raises an exception if the value is not found. (An example is given below.)

Example Code:

The code given above show on how to display String Find in Python

Output:

7

Python String Index or Python String Indexing

The index() method locates the first instance of a given variable.

If the value cannot be retrieved, the index() method throws an exception.

The only difference between the index() and find() methods is that the find() function returns -1 if the value cannot be located. (An example is given below.)

Example Code:

The code given above show you the example where in the text is the word “welcome”.

Output:

7

Python String Functions

The str() function creates a string from the provided value.

Example Code:

The code given above show you on how to convert the 3.5 into an string.

Output:

3.5

Python String Slice or Python String Slicing

The slice syntax can be used to return a range of characters.

To return a portion of the text, specify the start index and the end index, separated by a colon.

Example Code:

The code given above show you on how to get the characters from position 2 to position 5.

Output:

llo

Python String Join

The join() method combines all of the items in an iterable into a single string.

The separator must be given as a string.

Example Code:

The code given above will show you on how to join all items in a tuple into a string, using a hash character as separator.

Output:

Jude-Adones-Caren

Python String Trim

Trimming whitespaces from a string object is easy with Python’s three methods.

3 Methods of String Trim In Python:

  • strip() returns a new string with any preceding and trailing whitespaces, including tabs, removed (\t).
  • rstrip() returns a new string that is devoid of trailing whitespace. It’s easier to remember if you think of it as deleting white spaces from the string’s “right” side.
  • lstrip() returns a new string with leading whitespace removed, or whitespaces removed from the string’s “left” side.

Example Code:

The code given above will show you on how to trim whitespaces from the string in python.

Output:

String =’ abc ‘
After Removing Leading Whitespaces String =’abc ‘
After Removing Trailing Whitespaces String =’ abc’
After Trimming Whitespaces String =’abc’

Python String Interpolation

In this post, we’ll look into string interpolation in Python. Percent -formatting, sys.format(), string.Template, and f-strings are all options for formatting text strings in Python.

The process of substituting variable values into placeholders in a string is known as string interpolation. You might want to update the placeholder for name of person with an actual name if you have a template for saying hello to someone like “Hello Name of person, glad to meet you!” String interpolation is the name for this method.

f-strings

In Python 3.6, a new literal string interpolation technique was introduced, as well as a new literal prefix f. This new method of string formatting is both powerful and simple to use. It gives you access to Python expressions that are embedded inside string constants.

Example Code:

The literal prefix f in the preceding example tells Python to restore the value of two string variables named name and program inside braces. As a result, when we print, we receive the output seen above.

Output:

Hello World! This is Python

Python String StartsWith

With the help of examples, we will learn about the Python String startswith() method in this article.

If a string begins with the supplied prefix, the startswith() method returns True (string). If this is not the case, False is returned.

startswith() Parameters

The startswith() method can take up to three parameters:

  • prefix – To be checked string or tuple of strings
  • start (optional) – The position in the string where the prefix will be verified.
  • end (optional) – The place in the string where the prefix is to be checked.

startswith() Return Value

The method startswith() returns a boolean value.

  • If the string begins with the supplied prefix, it returns True.
  • If the string does not begin with the supplied prefix, it returns False.

Example Code:

The code given above is the example of startswith() without start and end parameters

Output:

False
True
True

Python String Lowercase or Python String To Lower

With the help of examples, we will learn about the Python String upper() method in this article.

The lower() method returns a string that has all uppercase characters converted to lowercase characters.

Example Code:

The code given above will display the returns lowercase string from the given string.

Output:

python is fun

Python String To Bytes

Inter conversions are widespread, but conversion of a string to bytes is increasingly prevalent these days due to the fact that we frequently require strings to be converted to bytes while working with files or Machine Learning (Pickle File). Let’s look at some examples of how this can be done.

The generic bytes function can be used to convert strings to bytes. Internally, this function refers to the CPython Library, which calls the encode function to transform the string to the chosen encoding.

Example Code:

The code given above is the conversion of String to Bytes in Python.

Output:

The original string : GFG is best
The byte converted string is : b’GFG is best’, type : <class ‘bytes’>

Parse Python String or Python String Parse

When you parse a string, you divide it into substrings using a delimiter. Example [“ab”,”cd”,”ef”] is the result of parsing “ab_cd_ef” by “_”.

Example Code:

The code given above is the example of the parse string in python.

Output:

[‘ab’, ‘cd’, ‘ef’]

Python String To DateTime or Python String To Date

In Python’s datetime class, the strptime() function converts a string representation of the date/time into a date object.

Example Code:

The following code sample demonstrates how to use Python’s strptime() method.

Output:

The date is 2021-10-26 16:39:19

Python String To Float

The float() method in Python can be used to convert a string to a float. It’s a built-in function for converting a floating point number to an object. Internally, the float() function calls the float() function of the provided object.

Example Code:

The code given above is the example to convert a string to float in python.

Output:

Float Value = 50.0

Python String Array

Multiple values can be stored in a single variable using arrays.

Example Code:

The code given above is the example of creating an array contaning car names.

Output:

[‘Ford’, ‘Volvo’, ‘BMW’]

Python String To Array

In Python, use the String.split() function to transform a String to an array. The String.split() method divides a String by a delimiter and returns the splitter elements as separate list items. The Python String split() function creates a list from a string. The separator can be specified; the default separator is any whitespace.

Example Code:

Because we haven’t specified a separator in this example, it uses whitespace as a separator, splits the String depending on that separator, and returns the list.

Output:

[‘IT’, ‘SOURCECODE’, ‘where’, ‘source’, ‘code’, ‘is’, ‘no’, ‘longer’, ‘a’, ‘problem’]

Python String To List

In this program, we will attempt to convert a given string to a list containing spaces or other special characters as determined by the user. The split() technique is used to do this.

Splitting the strings and storing them in the list is done with the split method. The built-in method uses the “delimiter” string as the delimiter string and produces a list of the words in the string. If no delimiter is supplied or is None, a different splitting mechanism is used: runs of consecutive whitespace are treated as a single separator, and if the string has leading or trailing whitespace, the result will not contain any empty strings at the beginning or end.

Example Code:

The code given above is the example of conversion of string to list in python.

Output:

[‘IT’, ‘SOURCE’, ‘CODE’]

Python String End or Python String EndsWith

If a string terminates with the specified suffix, the Python String endswith() method returns True; otherwise, it returns False.

Example Code:

The code given above is the example of the string end in python.

Output:

True

Python String Uppercase

The upper() function in Python changes all lowercase letters in a string to uppercase letters and returns the result. If all of the characters in a string are uppercase, the Python function isupper() returns true; otherwise, it returns false. Both can be used to format data that is case sensitive.

With the help of examples, we will learn about the Python String upper() method in this article.

Example Code:

The code given above is the example of string uppercase in python.

Output:

PYTHON IS FUN

Python String Is Empty

Because Python strings are immutable, they have more complicated handling when it comes to operations. It’s important to remember that a string with spaces is essentially an empty string with a non-zero length. This article also addressed the issue and proposed a solution.
Let’s look at few alternative approaches for determining whether a string is empty or not.

The most generic technique for checking for zero-length strings is to use len(). Even if it ignores the notion that a string with only spaces should be treated as an empty string if its length is greater than zero.

Example Code:

The code given above is the example of checking if the string is empty in python.

Output:

The zero length string without spaces is empty ? : Yes

By the way if you are new to python programming and you don’t know what would be the the Python IDE to use, I have here a list of Best Python IDE for Windows, Linux, Mac OS that will suit for you. I also have here How to Download and Install Latest Version of Python on Windows.

Inquiries

If you have any questions or suggestions about Python String : The Ultimate Guide For Beginners 2021, please feel free to leave a comment below.

Leave a Comment