PythonCommon Python Errors

Common Python Errors and Example Programs

In Python, there are several common built-in exceptions that every developer should understand. Here we will demonstrate 1 example for each kind of error, with detailed explanation.

1. ZeroDivisionError

error_zero_division.py
try:
    a = 10
    b = 0
    result = a / b
except ZeroDivisionError:
    print("Cannot divide by zero!")
output.txt
Cannot divide by zero!

2. ValueError

error_value.py
try:
    num = int("abc")
except ValueError:
    print("Invalid value: cannot convert string to integer.")
output.txt
Invalid value: cannot convert string to integer.

3. IndexError

error_index.py
try:
    lst = [10, 20, 30]
    print(lst[5])
except IndexError:
    print("List index out of range!")
output.txt
List index out of range!

4. KeyError

error_key.py
try:
    d = {"name": "Alice"}
    print(d["age"])
except KeyError:
    print("Key not found in dictionary!")
output.txt
Key not found in dictionary!

5. TypeError

error_type.py
try:
    result = "abc" + 5
except TypeError:
    print("Cannot add string and integer!")
output.txt
Cannot add string and integer!

6. FileNotFoundError

error_file_not_found.py
try:
    file = open("nonexistent_file.txt", "r")
except FileNotFoundError:
    print("File not found!")
output.txt
File not found!

7. AttributeError

error_attribute.py
try:
    x = 10
    x.append(5)
except AttributeError:
    print("AttributeError: 'int' object has no attribute 'append'")
output.txt
AttributeError: 'int' object has no attribute 'append'

Summary

  • Python raises different types of built-in exceptions for different error conditions.
  • Always handle these exceptions using structured try/except blocks.
  • Understanding common exceptions helps in writing robust, error-free applications.

Next, we will explore how to raise exceptions manually using raise keyword — an important part of custom error handling in Python.

Try, Except, Else, FinallyRaising Exceptions