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Common Python Errors Every Beginner Should Know

When writing Python programs, you may encounter different types of errors. Understanding these errors makes debugging much easier.

we'll learn about five common Python errors:

  1. SyntaxError
  2. NameError
  3. TypeError
  4. IndentationError
  5. TabError

1. SyntaxError

What is a SyntaxError?

A SyntaxError occurs when you break Python's grammar rules. Python cannot understand the code because it is written incorrectly.

Example 

if 10 > 5
    print("Hello")
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Output 

SyntaxError: expected ':'
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Why?

The colon (:) is missing after the if statement.

Correct Code 

if 10 > 5:
    print("Hello")
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2. NameError

What is a NameError?

A NameError occurs when you use a variable or function that has not been defined.

Example 

print(age)
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Output 

NameError: name 'age' is not defined
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Why?

The variable age was never created.

Correct Code 

age = 25
print(age)
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3. TypeError

What is a TypeError?

A TypeError occurs when an operation is performed on incompatible data types.

Example 

age = 20
name = "Vinoth"

print(age + name)
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Output 

TypeError: unsupported operand type(s) for +: 'int' and 'str'
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Why?

Python cannot add an integer (int) and a string (str).

Correct Code 

print(str(age) + name)
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4. IndentationError

What is an IndentationError?

An IndentationError occurs when Python expects an indented block, but the indentation is missing or incorrect.

Example 

def greet():
print("Hello")
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Output 

IndentationError: expected an indented block
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Why?

The print() statement should be inside the function and must be indented.

Correct Code 

def greet():
    print("Hello")
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5. TabError

What is a TabError?

A TabError occurs when you mix Tabs and Spaces for indentation in the same block of code.

Example 

def buy_grocery():
    print("Buying Grocery Items")
      return "Grocery Bag"
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Output 

TabError: inconsistent use of tabs and spaces in indentation
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Why?

  • The print() statement is indented using a Tab.
  • The return statement is indented using Spaces.

Python cannot determine whether both lines belong to the same block.

Correct Code 

def buy_grocery():
    print("Buying Grocery Items")
    return "Grocery Bag"
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Tip: Use 4 spaces for indentation throughout your Python program. Avoid mixing tabs and spaces.

Summary Table

Error Cause Example
SyntaxError Invalid Python syntax Missing : after if
NameError Variable or function not defined print(age)
TypeError Using incompatible data types 10 + "20"
IndentationError Missing or incorrect indentation Function body not indented
TabError Mixing tabs and spaces One line uses a tab, another uses spaces

Remember these common Python errors:

  • SyntaxError – Invalid syntax.
  • NameError – Undefined variable or function.
  • TypeError – Wrong data types.
  • IndentationError – Incorrect indentation.
  • TabError – Mixed tabs and spaces.

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