Working with operating system paths in Python - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

What is the output of joining paths?

Consider the following Python code using os.path.join. What will be printed?

Python

import os
path = os.path.join('folder', 'subfolder', 'file.txt')
print(path)

A "folder.subfolder.file.txt"

B "folder/subfolder/file.txt"

C "folder-subfolder-file.txt"

D "folder\\subfolder\\file.txt"

💡 Hint

Think about how paths are joined on Unix-like systems.

The os.path.join function joins parts of a path using the system's path separator. On Unix-like systems, it uses forward slashes (/). So the output will show forward slashes between parts.

❓ Predict Output

intermediate

What does os.path.basename return?

What will the following code print?

Python

import os
filename = os.path.basename('/home/user/docs/report.pdf')
print(filename)

A "report.pdf"

B "/home/user/docs/report.pdf"

C "/home/user/docs"

D "docs/report.pdf"

💡 Hint

Think about what the basename function extracts from a path.

os.path.basename returns the last part of the path, which is the file name with extension.

❓ Predict Output

advanced

What is the output of normpath with redundant separators?

What will this code print?

Python

import os
path = os.path.normpath('folder//subfolder/../file.txt')
print(path)

A "folder//file.txt"

B "folder/../file.txt"

C "folder/file.txt"

D "folder/subfolder/file.txt"

💡 Hint

Think about how normpath simplifies paths by removing redundant parts.

os.path.normpath removes redundant separators and resolves '..' to go up one directory, so 'folder//subfolder/../file.txt' becomes 'folder/file.txt'.

❓ Predict Output

advanced

What error does this code raise?

What error will this code raise?

Python

import os
path = os.path.join('folder', None, 'file.txt')
print(path)

A TypeError

B ValueError

C AttributeError

D No error, prints 'folder/None/file.txt'

💡 Hint

Consider what happens when you pass None to os.path.join.

Passing None to os.path.join causes a TypeError because it expects strings, bytes, or os.PathLike objects, not NoneType.

🧠 Conceptual

expert

How many items are in the list after splitting a path?

Given this code, how many items will the list parts contain?

Python

import os
path = '/usr/local/bin/python3'
parts = path.split(os.sep)
print(len(parts))

A 4

B 3

C 6

D 5

💡 Hint

Remember that splitting by '/' on an absolute path creates an empty string at the start.

Splitting '/usr/local/bin/python3' by '/' results in ['', 'usr', 'local', 'bin', 'python3'], which has 5 items.