with statement
- Python course
- Intermediate
- Lesson 67/116
- 5 min
Learn automatic close with with open(...) as f:.
The with statement closes automatically
Forgetting to call close() after opening a file is a common bug. The with statement solves this: when the block ends, the file is closed automatically. Write with open("f.txt", encoding="utf-8") as f: and the file object f is usable inside the block; it closes on exit.
Even if an error occurs, with still closes the file. That's why with is always recommended for file work. The code is shorter and safer.
Practice Write and read with with
Use two with blocks. In the first, open the file for writing: with open("hi.txt", "w", encoding="utf-8") as f: and inside the block write f.write("Hello"). In the second, open in read mode: with open("hi.txt", "r", encoding="utf-8") as f: and inside the block write print(f.read()). Do not call close().
Starter code
# with: write Hello to the file
# with: read the file and printSample solution
# with: write Hello to the file
with open("hi.txt", "w", encoding="utf-8") as f:
f.write("Hello")
# with: read the file and print
with open("hi.txt", "r", encoding="utf-8") as f:
print(f.read())Expected output
Hello
Multiple files in one with
You can open several files side by side in the same with: with open("a.txt") as fa, open("b.txt") as fb:. Both close at the end of the block.
Since Python 3.10 a parenthesized multi-line form exists: with (open("a.txt") as fa, open("b.txt") as fb):. This form is more readable and great for splitting long lines.
Questions and answers
Review the lesson questions together with their answers. To test yourself, solve the lesson interactively.
1 What is the main benefit of using with?
- The file closes automatically at block exit Correct answer
- The file size shrinks
- The operation uses less memory
- The file opens faster
Explanation: with closes the file automatically when the block exits; safe even on errors.
2 Match the with statement
| Term | Meaning |
|---|---|
with |
Automatic closing |
as |
Binding name |
open |
File opening |
close |
Manual closing |
3 Complete the with statement
____ open("f.txt", encoding="utf-8") as f:
print(f.read())with open("f.txt", encoding="utf-8") as f:
print(f.read())Explanation: The with statement closes the file automatically.