Python allows us to work with different data structures and write them to an external file.
In this tutorial, we will learn how to write a list to a file in Python
Table of Contents
- Using the write() function to write a list to a file in Python
- Using the writelines() function to write a list to a file in Python
- Using the pickle.dump() function to write a list to a file in Python
- Using the json.dump() function to write a list to a file in Python
- Using the unpack operator * to write a list to a file in Python
- Using the numpy.savetxt() function to write a list to a file in Python
Using the write() function to write a list to a file in Python
The write() function is used to write contents to a file in Python. We use the open() function to create a file object and open it in write mode. We can iterate through the list and write every element individually.
We implement this in the following code.
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lst = ["We","Love","Python"] with open(r'Desktop\Manav\Article\sample1.txt', 'w') as f: for item in lst: f.write("%s\n" % item) |
Output
Here is output of the program.
You need to change r'Desktop\Manav\Article\sample1.txt' to the path where you want to write list.
The %s is used to specify that the item is a string and \n adds a new line after every element.
Instead of iterating through the list, we can also use the join() function. The join() function will combine all the elements of the list after separating them with a specified character.
For example,
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lst = ["We","Love","Python"] with open('sample1.txt', 'w') as f: f.write("\n".join(lst)) |
When we open a file in write mode (using w), it clears the contents of the given file. If a file contains some contents and we want to preserve it then we should open the file in append mode.
See the code below.
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lst = ["We","Love","Python"] with open('sample1.txt', 'a') as f: f.write("\n".join(lst)) |
This way, we start writing the data to the list to the end of the file, without clearing any data which is present earlier.
