Invalid Syntax Error In Python [How To Fix With Examples]

In this Python tutorial, we will discuss everything about invalid syntax Python. We will see, when “syntaxerror: invalid syntax” error appears in Python. And also how to fix invalid syntax error in Python.

Table of Contents

Why invalid syntax error in Python?

An invalid syntax error in Python can appear for a multitude of reasons, some of which are:

Misspelled Keywords: Python has a set of reserved keywords that should be spelled correctly. For instance, typing ‘fro’ instead of ‘for’ will result in a syntax error.
Improper Indentation: Python uses indentation to differentiate between blocks of code. If your code is not indented correctly, Python will throw an error.
Incorrect Punctuation: Each statement in Python must end with a newline. If a statement is broken up incorrectly or punctuation such as colons and parentheses are misplaced, it can result in a syntax error.
Variable Names: If a variable name starts with a number or contains spaces or special characters (with the exception of underscores), it’s going to be a problem for Python.
Incorrect Function Calls: If functions are called without the correct number or type of arguments, Python will throw an error.

How to fix invalid syntax in Python

Here are a few examples, that we can follow to fix invalid syntax in Python.

Example 1: Misspelled Keywords

Incorrect:

fro i in range(10):
    print(i)

In the code above, ‘for’ is misspelled as ‘fro’, which results in a SyntaxError. Check out the output below:

Corrected:

for i in range(10):
    print(i)

Simply correcting the spelling of ‘for’ fixes the issue.

Example 2: Improper Indentation

Incorrect:

def foo():
print("Hello, World!")

Python uses indentation to indicate blocks of code. In the code above, the ‘print’ statement isn’t indented correctly and hence Python raises a SyntaxError.

Corrected:

def foo():
    print("Hello, World!")

By indenting the ‘print’ statement correctly under the function definition, the syntax error is resolved.

Example 3: Incorrect Punctuation

Incorrect:

if x == 10
    print("x is 10")

The ‘if’ statement is missing a colon at the end which causes a SyntaxError. You can see the output when you run the code like below:

Corrected:

if x == 10:
    print("x is 10")

Adding the missing colon resolves the syntax error.

Example 4: Incorrect Variable Names

Incorrect:

1var = "Invalid"

Variable names in Python cannot begin with a number. The above line will therefore raise a SyntaxError.

Corrected:

var1 = "Valid"

By changing the variable name to start with a character, the syntax error is resolved.

Example 5: Incorrect Function Calls

Incorrect:

print("Hello, World!", end = " ", "Goodbye, World!")

The print function does not accept multiple string arguments after a keyword argument. The above code will therefore raise a SyntaxError.

Corrected:

print("Hello, World!", end = " ")
print("Goodbye, World!")

Splitting the print statements into two corrects the issue.

Remember, the key to fixing syntax errors is carefully reading the error messages and understanding what Python is struggling to understand. With practice, you’ll find these become easier to spot and correct. I hope you can now fix the invalid syntax error in Python.