The glob module is an essential component of any data science or machine learning project and is widely used in various applications such as web development, data analysis, and scientific computing. Today we will learn what is python glob with examples, how to use the glob function, and the difference between glob and iglob.
What is glob module in python?
Python's glob module offers support for file name pattern matching. It provides a function called glob() that takes a pattern string as input and returns a list of filenames that match the pattern.
It allows you to match filenames against various patterns and perform operations like listing, searching, and sorting files that match a specific pattern. The glob module's patterns are comparable to shell globbing expressions and support numerous wildcard characters such as *,?, [], and [!]. So, it is a powerful tool for working with files and directories.
The glob module is frequently used in conjunction with the os module to handle file-related tasks such as reading and writing files, creating and removing directories, and so on. When working with enormous volumes of data or performing complex file operations based on patterns, the glob module comes in handy.
In addition to matching filenames against patterns, this module contains a number of useful functions for filtering and manipulating file paths. For example, the glob.glob function returns a list of all files that match a specific pattern, whereas the glob.iglob function iterates over the matching files in a more memory-efficient method.
How to use glob function?
The glob module's glob function is used to locate all file paths that match a given pattern. It provides a list of file names that match the specified pattern, which can subsequently be used for a variety of tasks such as reading and writing files, searching for specific information, and so on.
To use the glob function, first include the glob module in your Python script. After that, you may use the glob function to find all the files that match a specific pattern.
For example, the code below shows how to use the glob function to find all.txt files in a directory:
import glob # Find all .txt files in the current directory files = glob.glob('*.txt') # Print the list of matching files print(files)
The glob function takes a string as an input, which is the pattern to match. In this scenario, the pattern '*.txt' matches all files ending in '.txt' in the current directory. The glob function will return a list of all filenames that match this pattern.
Aside from matching filenames based on the file extension, the glob function can also match filenames based on other criteria such as the filename's prefix or suffix, or the presence of specified characters in the filename.
So, how to use the glob function to find all files in a directory that begin with 'data' and conclude with '.csv'. Here is an example:
import glob # Find all files in the current directory that start with 'data' and end with '.csv' files = glob.glob('data*.csv') # Print the list of matching files print(files)
The pattern 'data*.csv' in this example matches any files in the current directory that begin with 'data' and end with '.csv'. The glob function will return a list of all filenames matching this pattern.
The glob function can also be used to match files in a specific directory rather than simply the current directory. To accomplish this, include the path to the directory in the pattern that you supply to the glob function.
The following code shows how to use the glob function to find all.txt files in the '/data' directory:
import glob # Find all .txt files in the '/data' directory files = glob.glob('/data/*.txt') # Print the list of matching files print(files)
In this case, the pattern '/data/*.txt' matches all files ending in '.txt' in the '/data' directory. The glob function will return a list of all filenames matching this pattern.
What is the difference between glob and iglob?
Both the functions in Python's glob module are used to identify all file paths that match a given pattern. However, there are some significant differences between these two tasks that must be understood.
The glob function accepts a pattern as an argument and returns a list of all file names that match the pattern. This function loads all matching filenames into memory, which can be inefficient when working with big volumes of data or a large number of matching files. In these circumstances, utilizing glob can cause memory and performance difficulties.
The iglob function is similar to the glob function but returns an iterator rather than a list. Unlike the glob function, iglob does not load all matched filenames into memory all at once. Instead, it produces filenames one by one when they are requested, which saves a lot of memory.
The distinction between glob and iglob is best understood by examining their usage cases. The glob function is best suited for actions such as sorting or filtering that need operations on all matched filenames. The iglob function, on the other hand, is best suited for scenarios where you need to process the matched filenames one by one.
For example, if you need to read a huge number of files and execute some operation on each one, utilizing iglob instead of glob can save a lot of memory. You can use iglob to process the matched files one by one rather than loading all of the filenames into memory at once.
Also, you should learn how to get a list of all files in a directory where the glob module can be used in python.
Conclusion
So, in this article, we learned everything about the glob module in python with examples. Its glob function is handy for discovering files that match a specific pattern. You also now know how it is different from iglob. Happy Learning :)
