How to clear file in python

Clear File Contents with Python

To clear the contents of a file in Python, the easiest way is to open the file in write mode and do nothing.

with open("example.txt",'w') as f: pass

Another way you can erase all contents in a file is with the truncate() function.

with open("example.txt",'w') as f: f.truncate(0)

If you want to clear only certain lines from a file, you can use the following method.

with open("example.txt",'r+') as f: lines = f.readlines() f.seek(0) f.truncate(0) f.writelines(lines[5:]) #removes first 5 lines from file 

When working with files in Python, the ability to easily be able to modify and change the file content can be useful.

One such situation is if you want to clear a file and delete all of the contents in the file.

To clear the contents of a file in Python, the easiest way is to open the file in write mode and do nothing.

Below shows you how to delete all of the contents from a file in Python.

with open("example.txt",'w') as f: pass

Using truncate() to Clear File Contents in Python

You can also use the truncate() function to clear a file and remove all the content in a file.

Below shows you how to remove everything from a file with truncate() in Python.

with open("example.txt",'w') as f: f.truncate(0)

Remove Specific Lines from File in Python

If you want to remove specific lines from a file, then you can do the following.

with open("example.txt",'r+') as f: lines = f.readlines() f.seek(0) f.truncate(0) f.writelines(lines[5:]) #removes first 5 lines from file

Hopefully this article has been helpful for you to learn how to clear a file in Python.

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Очистка файла

Иногда возникают ситуации, когда надо произвести запись в файл, в котором уже находятся данные. Или просто удалить все содержимое. Рассмотрим, как выполнить очистку этого файла средствами Python 3.

Способы

Очистить файл в Python 3 можно следующими способами:

• При открытии использовать режим, в котором указатель находится в начале документа.
• Вручную переместить указатель в начальную позицию.
• Средствами операционной системы обнулить содержимое файла.

Рассмотрим эти варианты подробно.

При открытии

Когда файл открывается на запись, то указатель текущего положения в документе может быть расположен в начале или в конце документа. Если указатель в конце, то данные будут дописываться. Нас же интересует вариант, когда указатель расположен в начале.

Здесь w – указывает режим открытия файла на запись в текстовом режиме с размещением указателя в начале. После выполнения этого кода, если существовал указанный файл, то содержимое его очистится. Если его не было, то создастся новый пустой.

Перед закрытием, можно было добавить информацию. Она будет записана с начала файла, а не дописана в конец.

f = open('test.txt', 'w') f.write('something') f.close()

Если надо записывать данные в бинарный файл, то следует использовать режим “wb”.

Если же наоборот, нам нужно добавить информацию в конец файла. При этом старые данные чтобы остались. В этом случае к режиму следует добавить символ +. Режим открытия текстового документа будет “w+”, а бинарного “wb+”.

Дополнительную информацию по режимам открытия можно получить в отдельной статье на нашем сайте.

Перемещение указателя

Если мы открыли файл на запись и не знаем, в каком месте находится указатель. Возможно, мы уже записали какие то данные. Мы можем просто переместить указатель в начало и закрыть его. В этом случае документ будет пустым.

f = open('test.txt', 'w+') f.seek(0) f.close()

В этом примере открытие сделали специально в режиме дозаписи. После закрытия, даже если в файле были данные, они удалятся.

Вот еще пример, здесь мы записываем данные, потом переносим указатель в начало. После этого еще раз производим запись. В итоге, в конце работы, в файле будет только последняя сделанная запись. Те данные, которые были внесены вначале, благополучно удалятся.

f = open('test.txt', 'w+') f.write('something string') f.seek(0) f.write('new string') f.close()

Средствами ОС

Для очистки с помощью средств операционной системы воспользуемся стандартной библиотекой os. Вначале её надо подключить с помощью инструкции import os.

На linux должно пройти следующим образом.

import os os.system(r' >file.txt')

Можно воспользоваться командами cp или cat. Вот пример решения с помощью cat.

os.system(r'cat /dev/null>file.txt')

Если код исполняется на Windows, то решение может быть таким:

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Clear a File in Python

1. Use the truncate() Function to Clear the Contents of a File in Python
2. Use the write Mode to Clear the Contents of a File in Python

In this tutorial, we will introduce how to clear a file in Python.

Use the truncate() Function to Clear the Contents of a File in Python

The truncate() method in the Python file handling allows us to set the size of the current file to a specific number of bytes. We can pass the desired size to the function as arguments. To truncate a file, we need to open it in append or read mode. For example.

with open("sample.txt", 'r+') as f:  f.truncate(4) 

Notice that the file is opened in read and write mode. The above code resizes the sample file to 4 bytes. To clear all the contents of a file, we simply pass 0 to the function as shown below.

with open("sample.txt", 'r+') as f:  f.truncate(0) 

This method is handy when we want to read a file and remove its contents afterward. Also, note that if one needs to write to this file after erasing its elements, add f.seek(0) to move to the beginning of the file after the truncate() function.

Use the write Mode to Clear the Contents of a File in Python

In Python, when we open a file in write mode, it automatically clears all the file content. The following code shows how.

with open("sample.txt",'w') as f:  pass 

When we open the file in write mode, it automatically removes all the contents from the file. The pass keyword here specifies that there is no operation executed.

Another method of achieving the same is shown below:

Manav is a IT Professional who has a lot of experience as a core developer in many live projects. He is an avid learner who enjoys learning new things and sharing his findings whenever possible.

Related Article — Python File

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7 Effective Ways to Clear All Text from a File in Python

Learn how to delete all text from a file in Python using 7 effective methods, including truncate(), replace(), shutil module, tempfile module, and more. Get best practices for file handling too.

Clearing all text from a file in Python is an essential part of file handling. Whether you want to delete all text from a file or remove a specific line, word, or character, Python provides various methods to do it. In this blog post, we will discuss seven effective ways to clear all text from a file in Python.

Using the truncate() Method

The truncate() method is the easiest way to remove all lines from a file and set the file pointer to the beginning of the file. This method can also be used to delete the contents of a file before writing to it. The truncate() method resizes the stream to the given size in bytes or the current position. You can use the truncate() method with the file object to clear all text from a file in Python.

# Open the file in write mode file = open("file.txt", "w") # Clear all text from the file file.truncate(0) # Close the file file.close() 

Opening a File in Write Mode

opening a file in write mode erases all its content and prepares it to be newly written again. To delete data from a file in Python, open the file in read mode, get all the data from it, reopen the file in write mode, and write all data back except the data to be deleted. Creating a backup of a file before deleting its contents is a good practice.

# Open the file in read mode file = open("file.txt", "r") # Get all data from the file data = file.readlines() # Close the file file.close()# Open the file in write mode file = open("file.txt", "w") # Write all data back except the data to be deleted for line in data: if "delete this line" not in line: file.write(line) # Close the file file.close() 

How to create and delete a text file in python

Create and delete a text file in python#filehandlinginpython #createfile #deletefile
Duration: 3:39

Creating a New File

Another way to delete text from a file is to create a new file and write everything from the original file except the part to be erased. To delete all ‘ from a text file, use find-and-replace in a text editor. Use regular expressions to remove specific patterns or characters from a text file.

# Open the original file in read mode file = open("file.txt", "r") # Open the new file in write mode new_file = open("new_file.txt", "w") # Write everything from the original file except the part to be erased for line in file: new_file.write(line.replace("delete this line", "")) # Close both files file.close() new_file.close() 

Using the replace() Method

Use the replace() method to delete a phrase or text from a file. To delete a specific word from a text file, use the replace() method or create a temporary file.

# Open the file in read mode file = open("file.txt", "r") # Get all data from the file data = file.read() # Close the file file.close()# Use the replace() method to delete a phrase or text new_data = data.replace("delete this text", "")# Open the file in write mode file = open("file.txt", "w") # Write the new data to the file file.write(new_data) # Close the file file.close() 

Delete A Specific Line From A File

line from a file using Python (i.e. a line at a specific line number). Source code: https
Duration: 6:12

Using shutil Module

Python’s shutil module offers the remove() method to delete files from the file system. Use os.remove() method to delete a file from the file system. Use os.path.exists() method to check if a file exists before deleting it.

import os# Delete a file using the shutil module import shutil shutil.rmtree("file.txt")# Delete a file using the os module if os.path.exists("file.txt"): os.remove("file.txt") else: print("The file does not exist.") 

Removing Blank Lines

To remove blank lines from a text file, use the strip() function.

# Open the file in read mode file = open("file.txt", "r") # Get all data from the file data = file.readlines() # Close the file file.close()# Open the file in write mode file = open("file.txt", "w") # Remove blank lines using the strip() function for line in data: if line.strip(): file.write(line) # Close the file file.close() 

Using tempfile Module

Use the tempfile module to create and use temporary files.

import tempfile# Create a temporary file with tempfile.TemporaryFile(mode="w+t") as file: # Write data to the file file.write("This is a temporary file.") # Move the file pointer to the beginning of the file file.seek(0) # Read data from the file data = file.read() # Print the data print(data) 

Other helpful code examples for clearing all text from a file in Python can be found on various programming forums and websites.

In python, clearing all text from a file in python code example

fileVariable = open('textDocName.txt', 'r+') fileVariable.truncate(0) fileVariable.close()

In python, how to clear a text file in python code example

f = open('file.txt', 'r+') f.truncate(0) # need '0' when using r+

Conclusion

In this blog post, we have covered seven different ways to delete all text from a file in Python. We have discussed using the truncate() method, opening a file in write mode, creating a new file, using the replace() method, using the shutil module, removing blank lines, and using the tempfile module. We have also shared some best practices for file handling in python. Remember to be careful when using these methods, as deleting all text from a file is irreversible.

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