SyntaxError: unmatched parentheses

The error “SyntaxError: unmatched parentheses” occurs when Python detects an opening ( or closing ) parenthesis that does not have a matching pair. This issue can happen in various places, such as function calls, mathematical expressions, and list/tuple definitions.

This guide will explain the causes of this error and provide step-by-step solutions to fix it.

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1. Understanding the Error

Parentheses () are used for:
Function calls → print("Hello")
Mathematical expressions → (2 + 3) * 5
Grouping conditions → if (x > 5 and y < 10):
Lists, tuples, and dictionaries → my_tuple = (1, 2, 3)

If you forget to close an opening parenthesis ( or add an extra closing parenthesis ), Python will raise this error.

🔴 Incorrect Code (Error):

print("Hello"   # ❌ Missing closing parenthesis

🔴 Error Message:

SyntaxError: unmatched '('

✅ Corrected Code:

print("Hello")  # ✅ Parentheses are correctly closed

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2. Common Causes and Solutions

2.1. Forgetting to Close an Opening Parenthesis

An opening ( **without a closing ) causes an error.

❌ Incorrect Code:

print("Hello"  # ❌ Missing closing parenthesis

✅ Solution:

print("Hello")  # ✅ Closed properly

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2.2. Extra Closing Parenthesis

A closing ) **without an opening ( also causes an error.

❌ Incorrect Code:

print "Hello"))  # ❌ Extra closing parenthesis

✅ Solution:

print("Hello")  # ✅ Correct number of parentheses

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2.3. Nested Parentheses Not Closed Properly

If parentheses are nested incorrectly, Python cannot match them.

❌ Incorrect Code:

result = (2 + (3 * 4)  # ❌ Missing closing parenthesis

✅ Solution:

result = (2 + (3 * 4))  # ✅ Nested parentheses are correctly closed

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2.4. Incorrect Function Calls

If function calls are missing a closing parenthesis, Python will raise an error.

❌ Incorrect Code:

def add(a, b):
    return a + b

sum = add(5, 3  # ❌ Missing closing parenthesis

✅ Solution:

sum = add(5, 3)  # ✅ Parentheses correctly closed

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2.5. Incorrect Tuple or List Syntax

If you forget to close a tuple or list, Python will not understand where it ends.

❌ Incorrect Code:

my_tuple = (1, 2, 3  # ❌ Missing closing parenthesis

✅ Solution:

my_tuple = (1, 2, 3)  # ✅ Correctly closed

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2.6. Using Parentheses Incorrectly with if, while, and for Statements

Parentheses should only enclose conditions, not extend beyond the statement.

❌ Incorrect Code:

if (x > 5 and y < 10:  # ❌ Missing closing parenthesis
    print("Valid")

✅ Solution:

if (x > 5 and y < 10):  # ✅ Correctly closed condition
    print("Valid")

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2.7. Multiline Expressions Without Proper Closure

If you split a long expression across multiple lines, make sure all parentheses are properly closed.

❌ Incorrect Code:

result = (
    2 + 3
    * (4 + 5
)  # ❌ Parentheses are not balanced

✅ Solution:

result = (
    2 + 3
    * (4 + 5)
)  # ✅ Now correctly closed

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3. How to Fix the Error Step by Step

1. Count the opening and closing parentheses to ensure they match.
2. Use an IDE or code editor (like VS Code, PyCharm) to highlight unmatched parentheses.
3. Check nested parentheses carefully, especially in complex expressions.
4. Ensure function calls, tuples, lists, and conditions are correctly enclosed.
5. Format code properly, especially when using multiline expressions.

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4. Using an IDE to Avoid Errors

A good IDE (Integrated Development Environment) helps prevent syntax errors.

• VS Code – Highlights unmatched parentheses.
• PyCharm – Detects syntax errors in parentheses.
• Jupyter Notebook – Shows clear error messages with line numbers.