File Management in Python

Learning objectives

By the end of this pill you will be able to:

• check whether a file exists;
• retrieve a file’s name, extension and size;
• rename, copy and delete files;
• use the os, shutil and pathlib modules to work with files in Python.

Working with files in Python

In Python we can interact with files in many ways: not only reading and writing them, but also checking whether they exist, inspecting their name, extension and size. These operations are mainly done with the os, shutil and pathlib modules.

Checking whether a file exists

With os:

import os

if os.path.exists("data.txt"):
    print("The file exists")
else:
    print("The file does not exist")

With pathlib:

from pathlib import Path

file = Path("data.txt")
if file.exists():
    print("The file exists")

Separating name and extension

With os:

import os

name, ext = os.path.splitext("report.docx")
print("Name:", name)       # report
print("Extension:", ext)   # .docx

With pathlib:

file = Path("report.docx")
print(file.stem)   # report
print(file.suffix) # .docx

Getting the file size

With os:

import os

size = os.path.getsize("report.docx")
print("Size:", size, "bytes")

With pathlib:

file = Path("report.docx")
print("Size:", file.stat().st_size, "bytes")

Renaming, copying and deleting files

For managing files we can use functions from os and shutil.

Renaming a file:

import os

os.rename("old.txt", "new.txt")

Copying a file:

import shutil

shutil.copy("data.txt", "backup_data.txt")

Deleting a file:

import os

os.remove("old.txt")

With pathlib the same operations become very readable:

file = Path("data.txt")

# rename
file.rename("new_name.txt")

# copy
import shutil
shutil.copy(file, "copy.txt")

# delete
file.unlink()

Summary

• os.path and pathlib allow you to work with files.
• You can check existence and retrieve extension, name and size.
• With os and shutil you can rename, copy and delete files.
• pathlib offers a more modern and readable approach.