How to Read a File and Write Into a New File With New Line Python

Python File Handling

In Python, in that location is no need for importing external library to read and write files. Python provides an inbuilt function for creating, writing, and reading files.

In this file handling in Python tutorial, we will learn:

• How to Open a Text File in Python
• How to Create a Text File in Python
• How to Append Text File in Python
• How to Read Files in Python
• How to Read a File line by line in Python
• File Modes in Python

How to Open a Text File in Python

To open a file, you need to use the built-in open office. The Python file open office returns a file object that contains methods and attributes to perform various operations for opening files in Python.

Syntax of Python open file part

file_object  = open("filename", "way")

Here,

• filename: gives name of the file that the file object has opened.
• mode: aspect of a file object tells you which mode a file was opened in.

More details of these modes are explained below

How to Create a Text File in Python

With Write to file Python, you can create a .text files (guru99.txt) past using the code, we have demonstrated here:

Step i) Open the .txt file

f= open up("guru99.txt","w+")

• We declared the variable "f" to open a file named guru99.txt. Open takes ii arguments, the file that we want to open and a string that represents the kinds of permission or performance we desire to do on the file
• Here, nosotros used "w" letter in our argument, which indicates Python write to file and it will create file in Python if it does not exist in library
• Plus sign indicates both read and write for Python create file performance.

Step 2) Enter data into the file

for i in range(x):      f.write("This is line %d\r\n" % (i+one))

• We have a for loop that runs over a range of 10 numbers.
• Using the write function to enter information into the file.
• The output we want to iterate in the file is "this is line number", which nosotros declare with Python write file function and then per centum d (displays integer)
• And then basically we are putting in the line number that nosotros are writing, then putting it in a railroad vehicle return and a new line character

Step 3) Close the file instance

f.close()

• This will shut the instance of the file guru99.txt stored

Here is the result subsequently lawmaking execution for create text file in Python example:

How to Create a Text File in Python

When you click on your text file in our case "guru99.txt" it will expect something similar this

Example of how to create a text file in Python

How to Suspend Text File in Python

You can also append/add together a new text to the already existing file or a new file.

Step 1)

f=open("guru99.txt", "a+")

Once again if you could encounter a plus sign in the lawmaking, it indicates that it will create a new file if it does non exist. But in our case nosotros already accept the file, then nosotros are not required to create a new file for Python suspend to file performance.

Pace 2)

for i in range(2):      f.write("Appended line %d\r\n" % (i+one))

This will write data into the file in append manner.

How to Append Text File in Python

You can see the output in "guru99.txt" file. The output of the lawmaking is that earlier file is appended with new data by Python append to file performance.

Example of How to Suspend Text File in Python

How to Read Files in Python

Yous tin can read a file in Python by calling .txt file in a "read manner"(r).

Stride ane) Open up the file in Read mode

f=open("guru99.txt", "r")

Footstep 2) We apply the mode office in the code to check that the file is in open up style. If yeah, we go along ahead

if f.mode == 'r':

Footstep 3) Use f.read to read file data and store it in variable content for reading files in Python

contents =f.read()

Stride 4) Print contents for Python read text file

Hither is the output of the read file Python example:

How to Read Files in Python

How to Read a File line past line in Python

Yous tin can also read your .txt file line by line if your data is too big to read. readlines() lawmaking volition segregate your information in easy to read mode.

How to Read a File line by line in Python

When you run the code (f1=f.readlines()) to read file line past line in Python, it will carve up each line and present the file in a readable format. In our case the line is brusque and readable, the output will look like to the read fashion. But if there is a complex data file which is not readable, this piece of code could be useful.

File Modes in Python

Following are the various File Modes in Python:

Mode	Clarification
'r'	This is the default mode. It Opens file for reading.
'westward'	This Mode Opens file for writing. If file does not exist, it creates a new file. If file exists information technology truncates the file.
'10'	Creates a new file. If file already exists, the operation fails.
'a'	Open file in append style. If file does not exist, it creates a new file.
't'	This is the default mode. Information technology opens in text mode.
'b'	This opens in binary manner.
'+'	This will open a file for reading and writing (updating)

Hither is the complete lawmaking for Python print() to File Example

Python 2 Example

def master():      f= open up("guru99.txt","due west+")      #f=open("guru99.txt","a+")      for i in range(10):          f.write("This is line %d\r\northward" % (i+1))      f.close()         #Open up the file dorsum and read the contents      #f=open("guru99.txt", "r")      #   if f.mode == 'r':       #     contents =f.read()      #     print contents      #or, readlines reads the private line into a list      #fl =f.readlines()      #for x in fl:      #print ten if __name__== "__main__":   main()

Python 3 Example

Below is another Python print() to File Example:

def main():     f= open("guru99.txt","west+")     #f=open("guru99.txt","a+")     for i in range(10):          f.write("This is line %d\r\due north" % (i+1))     f.close()     #Open the file back and read the contents     #f=open up("guru99.txt", "r")     #if f.way == 'r':     #   contents =f.read()     #    print (contents)     #or, readlines reads the individual line into a listing     #fl =f.readlines()     #for x in fl:     #impress(x) if __name__== "__main__":   main()

Summary

• Python allows y'all to read, write and delete files
• Use the function open("filename","w+") for Python create text file. The + tells the python interpreter for Python open text file with read and write permissions.
• To append information to an existing file or Python impress to file operation, use the command open("Filename", "a")
• Apply the Python read from file office to read the Entire contents of a file
• Use the readlines part to read the content of the file one by one.

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Source: https://www.guru99.com/reading-and-writing-files-in-python.html

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