try/except
- Python course
- Beginner
- Lesson 100/116
- 5 min
Learn to catch exceptions with try/except.
Catch errors with try/except
Code inside a try block may raise an error; the except block catches it so the program keeps running:
try:
x = int("abc")
except:
print("Geçersiz giriş")Here int("abc") raises ValueError; the except block catches it and prints a message. Without try the program would stop.
This is the standard approach for operations that may fail, such as user input and file reading.
Catching specific error types
A bare except: catches all errors, but this is dangerous — it hides unexpected bugs. It is better to catch a specific type:
try:
x = int("abc")
except ValueError:
print("Sayı değil")Here only ValueError is caught. If another error (say TypeError) occurs, the program still crashes — which is the desired behaviour.
Multiple except blocks can also be written: one per type.
Practice Catch ValueError and print a message
Inside a try block write x = int("abc"). Inside an except ValueError: block write print("hata").
Starter code
# open a try block
# attempt the int conversion
# catch with except ValueErrorSample solution
try:
x = int("abc")
except ValueError:
print("hata")Expected output
hata
Questions and answers
Review the lesson questions together with their answers. To test yourself, solve the lesson interactively.
1 What happens if an error occurs in the try block?
- The program crashes
- The except block runs Correct answer
- The try block reruns
- Nothing happens
Explanation: When an error occurs Python leaves the try block and jumps to except.
2 Complete the except keyword
try:
x = int("abc")
____:
print("hata")try:
x = int("abc")
except:
print("hata")Explanation: The except block catches the error inside try.
3 Match try/except concepts
| Term | Meaning |
|---|---|
try |
Code that may fail |
except |
Catches the error |
ValueError |
Specific error type |
int("abc") |
Raises ValueError |