How to Open a File and Read Line by Line in Python

In this Python tutorial, we will learn, how to read a file line past line in Python with a few examples. Autonomously from Python read a file line by line we volition also cover the below topics:

• Python read file line by line
• Python read file line by line into array
• Python read file line by line into a lexicon
• Python read file line by line and search string
• Python read file line by line without a newline
• Python read file line past line into a list
• Python read file line by line into a set
• Python read file line by line and write to some other file
• Read file line by line for loop python

Python read file line by line

Now, we can come across how to read file line by line in python.

• In this example, I accept taken a line as ["Welcome\due north","to\north","Pythonguides\northward"] , and to open the file , I accept used file = open('line.txt', 'w') and 'westward' way to write the lines. Here line.txt is the name of the file.
• To read the lines, I take used Lines = file.readlines(), for loop, is used.

Example:

          Line = ["Welcome\n","to\northward","Pythonguides\due north"] file = open('line.txt', 'w') file.writelines(Line) file.close() file = open('line.txt', 'r') Lines = file.readlines() for line in Lines: 	impress(line)                  

To go output, I have used print(line). In the below screenshot, we can see the line from the file as the output.

Python read file line by line

This is how we can read file line past line in Python.

Check out Python binary tree implementation and How to read video frames in Python.

Python read file line past line into array

At present, we can see how to read file line past line into array in python.

• In this example, I have defined a function every bit fruits and an argument fruitsname is passed.
• An empty array is defined and the statement is opened as f and to read the line. The for line in f is used and to append the line into the array, assortment.append is used.
• The fruits file is passed as the parameter in the function.

Example:

          def fruits(fruitsname):         assortment = []         with open(fruitsname) every bit f:                    for line in f:                         array.suspend(line)                 impress(assortment) fruits('fruits.txt')        

The below screenshot shows the content of the file

How to read file line by line into array in Python

The line which is nowadays in the file is appended into the array as the output. You can refer to the below screenshot for the output.

Python read file line by line into array

This code, nosotros tin use to read file line by line into array in Python.

Python read file line past line into lexicon

At present, nosotros can see how to read file line by line into dictionary into python.

• In this example, An empty lexicon is declared and the file dictionary.txt is opened.
• The for line in file is used to read the file line by line and key, value is assigned line.split() is used to split the list.
• To assigned the key and value, I take used dictionary[central] = value.
• To impress the dictionary, I have used print(dictionary).

Instance:

          dictionary = {} file = open("dictionary.txt") for line in file:     key, value = line.split()     dictionary[key] = value print(dictionary)        

The beneath screenshot show the content of the file.

Python read file line past line into dictionary

Here, we can run across the output as the dictionary is printed by reading the file. You can refer to the below screenshot for the output.

Python read file line by line into dictionary

This is how to read file line by line into lexicon in Python.

You may like to read, Python program to observe sum of n numbers and How to add two numbers in Python.

Python read file line by line and search cord

Here, we can see how to read file line by line and search string in python.

• In this example, I have defined a function as a file and passed the arguments filename and search.
• To search the cord, I accept opened the file cord.txt and to read the file, I have used for line in read to search the string.
• If the string is in line render Truthful and return Imitation if the word 'Hi' is present in the file it prints string present in the file else the string not present in the file.

Example:

          def file(file_name, search):      with open up("string.txt", 'r') as read:         for line in read:             if search in line:                 render True       render Simulated if file('string.txt', 'Hello'):     impress('string nowadays in the file') else:     impress('Cord not present in the file')        

The below screenshot testify the content of the file.

Python read file line past line and search string

As the string "How-do-you-do" is present in the file, we can see the output every bit Cord present in the file. You lot can refer to the below screenshot for the output.

Python read file line by line and search string

This is how to read file line by line and search cord in Python.

Python read file line by line without a newline

Now, we tin run into how to read file line by line without a newline in python.

• In this example, I have opened the file cord.txt and used "r" mode to read the file.
• To read the file line by line without a newline, I have used .replace('\n').
• To get the output print(string) is used.

Instance:

          file=open("string.txt","r")   string=file.read().supercede('\n','')   print(string)                  

The below screenshot show the content of the file.

Python read file line by line without a newline

The beneath screenshot show that the file is read without newline as the output. The beneath screenshot shows the output.

Python read file line past line without a newline

The above code, we can use to read file line by line without a newline in Python.

Python read file line by line into a list

Permit'southward run across how to read file line by line into a list in python.

• In this case, I have opened a file number.txt and 'r' mode to read the file as f, and an empty list is divers as list = [ ] and to read line by line for line in f is used.
• To append the line from the file into the list, I have used lines.append(line.strip()) the line.strip is used.
• The line.strip() is used to copy the string and remove the characters. To get the output, impress(lines) is used.

Example:

          with open ("number.txt",'r' ) as f:     list = []     for line in f:         lines.suspend(line.strip())         print(lines)        

The below screenshot show the content of the file number.txt.

Python read file line by line into a listing

In the below screenshot, we can that the content from the file number.txt is appended in the list equally the output.

Python read file line by line into a list

The above code, nosotros can use to read file line past line into a list in Python.

Python read file line by line into a gear up

Now, we can run across how to read file line past line into a set in python.

• In this example, a set is used to read the file into a prepare the content from the file chocolate.txt is read by using .read() and .split up() is used to carve up the string.
• To become the output, I have used print(chocolate).

Example:

          chocolate =  set(open('chocolate.txt').read().split()) print(chocolate)                  

The below screenshot bear witness the content of the file.

Python read file line by line into a set

The content from the file chocolate.txt is appended into the ready every bit the output. You can refer to the below screenshot for the output.

Python read file line past line into a set up

This is how to read file line past line into a set in Python.

Python read file line by line and write to another file

Here, we tin meet how to read file line past line and write to another file in python.

• In this example, I have opened the file chocolate.txt as f1.
• To write the content into some other file, I accept opened another file equally newfile.txt and f.write is used to write the file, and f.read is used to read the file.
• The .strip() is used to remove the graphic symbol from the left and right of the argument.

Example:

          with open("chocolate.txt") as f1,\         open("newfile.txt", "due west") as f:     f.write(f1.read().strip())        

The below screenshot shows the content of the file chocolate.txt.

In the below screenshot, nosotros tin can meet that the content from the file chocolate.txt into newfile.txt.

Python read file line past line and write to some other file

This is how to read file line by line and write to some other file in Python.

Read file line by line for loop python

Now, we can come across how to Read file line by line for loop in python.

In this example, I have opened a file python.txt as f and for loop is used as for line in f to read the line of the file.

Example:

          with open('python.txt') equally f:      for line in f:        print(line)        

The below screenshot shows the content of the file

Read file line by line for loop python

All the lines from the file python.txt are read every bit the output. Y'all tin refer to the beneath screenshot for the output.

Read file line by line python for loop

The above code, we can use to read file line by line for loop in Python.

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In this tutorial, we have learned about Python read a file line by line instance, and also we have covered these topics:

• Python read file line by line
• Python read file line by line into array
• Python read file line by line into a dictionary
• Python read file line by line and search string
• Python read file line by line without a newline
• Python read file line by line into a listing
• Python read file line past line into a set
• Python read file line by line and write to some other file
• Read file line past line for loop python

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