{"id":12932,"date":"2020-11-19T18:30:06","date_gmt":"2020-11-20T02:30:06","guid":{"rendered":"https:\/\/careerkarma.com\/blog\/?p=12932"},"modified":"2023-12-01T04:04:14","modified_gmt":"2023-12-01T12:04:14","slug":"python-list-files-in-directory","status":"publish","type":"post","link":"https:\/\/careerkarma.com\/blog\/python-list-files-in-directory\/","title":{"rendered":"Python List Files in a Directory: Step-By-Step Guide"},"content":{"rendered":"\n

The Python os library is used to list the files in a directory. The Python os.listdir() method returns a list of every file and folder in a directory. os.walk() function returns a list of every file in an entire file tree. <\/em><\/p>\n\n\n\n

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Often, when you\u2019re working with files in Python, you\u2019ll encounter situations where you want to list the files in a directory. For instance, you may want to find all of the Python files in a folder.<\/p>\n\n\n\n

The Python os library offers a number of methods that can be used to list files in a directory. This tutorial will discuss how to use os.listdir() to get the files and folders in a director. We’ll also talk about using os.walk()<\/em> to get the files and folders in a directory and<\/em> in its subdirectories.\n\n<\/p>\n\n\n\n

Python os Library<\/h2>\n\n\n\n

The Python os library provides a number of functions that you can use to work with operating systems. The functions included in the os module work on any modern operating system, whether it is Windows, Linux, or Mac.\n\n<\/p>\n\n\n\n

Since os is an external library, we need to import it into our code before we start using it. We can do so using a Python import statement<\/a>:\n\n<\/p>\n\n\n\n

import os<\/pre><\/div>\n\n\n\n
Now that we\u2019ve imported the os library into our code, we can start using its functions to list items in a directory.\n\n<\/p>\n\n\n\n
Python os.listdir()<\/h2>\n\n\n\n
In Python, the os.listdir()<\/em> method lists files and folders in a given directory. The method does not return special entries such as \u2018.\u2019 and \u2018..\u2019, which the operating system uses to navigate through different directories.<\/p>\n\n\n\n
os.listdir() also does not return files and folders beyond the first level of folders. In other words, os.listdir()<\/em> does not return anything within subfolders discovered by the method.<\/p>\n\n\n\n
The os.listdir() function accepts one parameter: the file path of the directory whose file and folder names you want to retrieve. \n\n<\/p>\n\n\n\n
Here\u2019s the syntax for the listdir method:<\/p>\n\n\n\n
os.listdir(path)<\/pre><\/div>\n\n\n\n
Let\u2019s walk through an example to showcase how to use this method in a Python program. <\/p>\n\n\n\n
os.listdir() Python Example<\/h3>\n\n\n\n
Say that we are creating a program that analyzes the stock market performance of Netflix over the last decade. We have a folder (name: \/home\/data_analysis\/netflix) with all of our raw data, and before our program starts running, we want to check to make sure that the file raw_data_2019.csv<\/em> exists within that folder. <\/p>\n\n\n\n
In order to function properly, our program needs that particular file to be stored in that particular folder.\n\n<\/p>\n\n\n\n
We could use the following code to retrieve a list of the files in the \/home\/data_analysis\/netflix<\/em> work directory:<\/p>\n\n\n\n
import os\n\npath = '\/home\/data_analysis\/netflix'\n\nfiles = os.listdir(path)\n\nfor f in files:\n\tprint(f)\n<\/pre><\/div>\n\n\n\n
Our program retrieves a list of all files and folders in the specified directory and returns the following:<\/p>\n\n\n\n
README.md\napp.py\nraw_data_2016.csv\nraw_data_2017.csv\nraw_data_2018.csv\nraw_data_2019.csv\nprocessed_data\n<\/pre><\/div>\n\n\n\n
Now, we can check to see if the file raw_data_2019.csv<\/em> is in the folder. As you can see, it is.\n\n<\/p>\n\n\n\n
Let\u2019s break down our code. On the first line, we import the os module, which we need to do in order to access the os.listdir() <\/em>function. Then, we declare a Python variable<\/a> called path<\/em>, which stores the name of the path whose contents we want to retrieve.\n\n<\/p>\n\n\n\n
On the next line, we use the os.listdir() method to get a list of the files and folders in the \/home\/data_analysis\/netflix<\/em> directory. Finally, we create a Python for loop<\/a>. This loop iterates through every item in the list produced by os.listdir()<\/em>. We print out the name of each file to the console using a Python print() statement<\/a>.\n\n<\/p>\n\n\n\n
The \/home\/data_analysis\/netflix<\/em> directory contained six files and one directory. The directory is called processed_data<\/em> and is distinguishable from the other files because it does not have an extension.\n\n<\/p>\n\n\n\n
Python os.walk()<\/h2>\n\n\n\n
The os.walk() <\/em>function retrieves a list of files contained within a tree. The method iterates over each directory in a tree. Then, os.walk() returns the name of every file and folder within a directory and any of its subdirectories.\n\n<\/p>\n\n\n\n
The syntax for the os.walk()<\/em> method is as follows:<\/p>\n\n\n\n
os.walk(top, topdown, onerror, followlinks)<\/pre><\/div>\n\n\n\n
The os.walk()<\/em> method accepts four parameters:\n\n<\/p>\n\n\n\n