Read in Text File for Variables Python 3

Table of Contents Hide

1. Steps to Read Text File in Python
   1. Python open() function
   2. Methods for Reading file contents
   3. Python close() function
2. Examples for Reading a Text file in Python
   1. Example 1 – Read the entire text file using the read() office
   2. Instance 2 – Read the specific length of characters in a text file using the read() function
   3. Example three – Read a single line in a file using the readline() part
   4. Instance 4- Read text file line by line using the readline() function
   5. Example 5 – Read all the lines as a list in a file using the readlines() function

Python provides congenital-in functions to perform file operations, such as creating, reading, and writing files. There are mainly ii types of files that Python can handle, normal text files and binary files. In this tutorial, nosotros will take a look at how to read text files in Python.

Steps to Read Text File in Python

In Python, to read a text file, you lot need to follow the below steps.

Step 1: The file needs to exist opened for reading using the open() method and pass a file path to the function.

Stride 2: The next step is to read the file, and this tin be achieved using several born methods such as read() , readline() , readlines() .

Step three: One time the read operation is performed, the text file must exist closed using the close() office.

Now that we take seen the steps to read the file content let's understand each of these methods before getting into examples.

Python open() function

The open() function opens the file if possible and returns the corresponding file object.

Syntax – open(file, mode='r', buffering=-1, encoding=None, errors=None, newline=None, closefd=True, opener=None)

The open() office has a lot of parameters. Permit's take a look at the necessary params for reading the text file. It opens the file in a specified mode and returns a file object.

Parameters

• file – path like object which represents the file path
• way (Optional) – The mode is an optional parameter. Information technology'due south a cord that specifies the mode in which you want to open up the file.

Mode	Clarification
'r'	Open a file for read mode (default if mode is non specified)
'w'	Open a file for writing. Python will create a new file if does not exist or truncates a file content if file exists
'10'	Open a file for sectional cosmos.
'a'	Open a file for appending the text. Creates a new file if file does not exist.
't'	Open up a file in text manner. (default)
'b'	Open up a file in binary style.
'+'	Open a file for updating (reading and writing)

Example

              file = open up('C:\hello.txt','r')            

Methods for Reading file contents

There are three means to read information from a text file.

1. read() : The read() part returns the read bytes in the grade of string. This method is useful when you have a small file, and y'all desire to read the specified bytes or unabridged file and shop it into a string variable.
2. readline() : The readline() role returns one line from a text file and retuns in the class of string.
3. readlines() : The readlines() function reads all the lines from the text file and returns each line as a string chemical element in a listing.

Python close() part

The file will remain open up until yous close the file using the close() function. It is a must and best exercise to perform this operation subsequently reading the information from the file every bit information technology frees up the retention infinite caused by that file. Otherwise, it may crusade an unhandled exception.

Examples for Reading a Text file in Python

Example 1 – Read the entire text file using the read() office

In the below example, nosotros are reading the entire text file using the read() method. The file tin be opened in the read mode or in a text mode to read the data, and information technology can be stored in the string variable.

              # Program to read the entire file using read() function file = open up("python.txt", "r") content = file.read() impress(content) file.close()   # Program to read the entire file (accented path) using read() part file = open("C:/Projects/Tryouts/python.txt", "r") content = file.read() print(content) file.shut()            

Output

              Dear User,  Welcome to Python Tutorial  Take a great learning !!!  Cheers            

Example 2 – Read the specific length of characters in a text file using the read() role

There are times where yous need to read the specific bytes in a file. In that case, you tin use the read() function by specifying the bytes. The method will output just the specified bytes of characters in a file, equally shown beneath.

              # Program to read the specific length  # of characters in a file using read() office file = open("python.txt", "r") content = file.read(xx) impress(content) file.close()                          

Output

              Dear User,  Welcome            

Example iii – Read a unmarried line in a file using the readline() part

If you want to read a single line in a file, then you could achieve this using readline() function. You also use this method to retrieve specific bytes of characters in a line, similar to the read() method.

              # Program to read single line in a file using readline() function file = open("python.txt", "r") content = file.readline() print(content) file.close()            

Output

              Dear User,                          

Case 4- Read text file line by line using the readline() role

If you lot want to traverse the file line by line and output in whatsoever format, so you could utilise the while loop with the readline() method as shown below. This is the most constructive fashion to read the text file line by line in Python.

              # Program to read all the lines in a file using readline() function file = open up("python.txt", "r") while True: 	content=file.readline() 	if not content: 		pause 	print(content) file.close()                          

Output

              Dear User,  Welcome to Python Tutorial  Have a great learning !!!  Cheers            

Example 5 – Read all the lines as a list in a file using the readlines() office

The readlines() method will read all the lines in the file and outputs in a list of strings, as shown beneath. Later y'all tin can use the listing to traverse and extract the specified content from the listing.

              # Programme to read all the lines every bit a list in a file #  using readlines() function  file = open up("python.txt", "r") content=file.readlines() print(content) file.close()                          

Output

              ['Dear User,\n', 'Welcome to Python Tutorial\north', 'Take a bang-up learning !!!\n', 'Thank you']            

Related Tags

• close(),
• fashion,
• open(),
• read file content,
• read(),
• readline(),
• readlines()

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