Python open two file

Open Multiple Files Using with open in Python

To open multiple files in Python, you can use the standard with open() as name syntax and for each additional file you want to open, add a comma in between the with open statements.

with open("file1.txt","w") as f1, open("file2.txt","w") as f2: #do stuff here

When working with files in Python, the ability to open multiple files can sometimes be useful as you may need information from different files.

It is well known that you can use with open to open a file, read from it or write to it.

For opening multiple files, all you need to do is add a comma in between the with open blocks.

Below shows you an example of how you can open multiple files using with open in Python.

with open("file1.txt","w") as f1, open("file2.txt","w") as f2: #do stuff here

How to Open More than Two Files at Once in Python

If you want to open more than two files at once in Python, then you can take the example above and add to it.

As you saw above, you just need to put a comma in between the with open statements to open multiple files.

Therefore, if you want to open more than two files, then you would just add another file at the end of your line.

Below shows you how to open three files in Python using with open

with open("file1.txt","w") as f1, open("file2.txt","w") as f2, open("file3.txt", "w") as f3: #do stuff here

Hopefully this article has been useful for you to learn how to open multiple files in Python.

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Open & Read Multiple Files Simultaneously Using with Statement In Python.

We use files for future use of our data by permanently storing them on optical drives, hard drives, or other types of storage devices.

Since we store our data in the files, sometimes we need them to read, write, or see our data.

For such file operations, in Python, we have a built-in function, which can help in opening a file, performing reading and writing operations on a file, and even closing the file after the task is completed.

Introduction

In this article, we gonna discuss the ways how we can open multiple files using the with statement in Python?

Let’s explore the ways and write some code.

Using open() function

Well, the first way we gonna discuss is the use of Python’s in-built open() function.

If you are familiar with the open() function, then you might know that it takes only one file path at a time.

Here’s the syntax:

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

Hence, we cannot pass multiple files path and if we try to do so then we get an error.

But there is a way, we can use the with statement to open and read multiple files using the open() function.

Here’s the code:

• with open(«first.txt») as file_1, open(«second.txt») as file_2, open(«third.txt») as file_3 : Here, we used open() function for each file which is wrapped within with statement.
• f1 = file_1.read() f2 = file_2.read() f3 = file_3.read() : Then we used read() function and store them in the variable.
• for lines in f1, f2, f3 : We used the for loop to iterate over the contents, in each file.
• print(lines) : Then we finally print the contents of each file.

Here’s the output:

What if we have lots of files, which we have to open and read simultaneously, then we have to write more lines of code which in turn kinda gets messy, and it’s not a good practice.

Well, we have another way of doing the same operation with lesser lines of code.

Using fileinput Module

First of all, fileinput module is a built-in module in Python, so you don’t need to install it explicitly.

fileinput — Iterate over lines from multiple input streams

Using the open() function to open multiple files simultaneously can be good but it’s not convenient.

Instead of using the first way, we can use fileinput module.

Let’s dive into the code and learn the use case:

• import fileinput : Since it’s a module, we have to import it to get started.
• with fileinput.input(files=(‘first.txt’, ‘second.txt’,’third.txt’)) as f : We are calling here input method from fileinput module and specifying our files into it which we wrapped within with statement.
• for line in f : Here we are using for loop to iterate over the contents of our file.
• print(line) : Finally printing those content.

for more details about fileinput module Click here.

Here’s the output:

The output is the same because we used the same files which we used above.

Note: This module opens the file in read mode only, we cannot open the files in writing mode. It must be one of ‘r’ , ‘rU’ , ‘U’ , and ‘rb’ .

Conclusion

We carried out the same task but we used different approaches to handle them. Both ways are quite good.

We learned here two ways to deal with reading and opening multiple files. One is using the open() function and another was using the fileinput module.

But every function and module has its own pros and cons.

We can’t use Python’s open() function to open multiple files until and unless we use the with statement with it but if we have lots of files then the code will get kinda messy.

And for fileinput module, we get the same task done with lesser lines of code but it can be used for only read mode.

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Конструкция with#

В Python существует более удобный способ работы с файлами, чем те, которые использовались до сих пор — конструкция with :

In [1]: with open('r1.txt', 'r') as f: . for line in f: . print(line) . ! service timestamps debug datetime msec localtime show-timezone year service timestamps log datetime msec localtime show-timezone year service password-encryption service sequence-numbers ! no ip domain lookup ! ip ssh version 2 !

Кроме того, конструкция with гарантирует закрытие файла автоматически.

Обратите внимание на то, как считываются строки файла:

Когда с файлом нужно работать построчно, лучше использовать такой вариант.

В предыдущем выводе, между строками файла были лишние пустые строки, так как print добавляет ещё один перевод строки.

Чтобы избавиться от этого, можно использовать метод rstrip :

In [2]: with open('r1.txt', 'r') as f: . for line in f: . print(line.rstrip()) . ! service timestamps debug datetime msec localtime show-timezone year service timestamps log datetime msec localtime show-timezone year service password-encryption service sequence-numbers ! no ip domain lookup ! ip ssh version 2 ! In [3]: f.closed Out[3]: True

И конечно же, с конструкцией with можно использовать не только такой построчный вариант считывания, все методы, которые рассматривались до этого, также работают:

In [4]: with open('r1.txt', 'r') as f: . print(f.read()) . ! service timestamps debug datetime msec localtime show-timezone year service timestamps log datetime msec localtime show-timezone year service password-encryption service sequence-numbers ! no ip domain lookup ! ip ssh version 2 !

Открытие двух файлов#

Иногда нужно работать одновременно с двумя файлами. Например, надо записать некоторые строки из одного файла, в другой.

В таком случае, в блоке with можно открывать два файла таким образом:

In [5]: with open('r1.txt') as src, open('result.txt', 'w') as dest: . : for line in src: . : if line.startswith('service'): . : dest.write(line) . : In [6]: cat result.txt service timestamps debug datetime msec localtime show-timezone year service timestamps log datetime msec localtime show-timezone year service password-encryption service sequence-numbers 

Это равнозначно таким двум блокам with:

In [7]: with open('r1.txt') as src: . : with open('result.txt', 'w') as dest: . : for line in src: . : if line.startswith('service'): . : dest.write(line) . : 

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