Reasons for “Cannot Convert String To Float” In Python

Below are some of the reasons why this error occurs in Python:

• Non-Numeric Characters
• Comma as Decimal Separator
• Whitespace or Leading/Trailing Character

Non-Numeric Characters

Below, the code raises a “ValueError” because the string “123.45abc” contains non-numeric characters, preventing successful conversion to a float.

Output:

Hangup (SIGHUP)
Traceback (most recent call last):
  File "Solution.py", line 3, in <module>
    print(float(a))
ValueError: could not convert string to float: '123.45abc'

Comma as Decimal Separator

Below, code will raise a `ValueError` because the string “1,234.56” includes a comma as a thousand separator, making it an invalid input for converting to a float in Python.

Output:

Hangup (SIGHUP)
Traceback (most recent call last):
  File "Solution.py", line 3, in <module>
    print(float(a))
ValueError: could not convert string to float: '1,234.56'

Whitespace or Leading/Trailing Characters

Below, code will raise a `ValueError` because the string ’67 . 89′ contains spaces between the digits, making it an invalid input for converting to a float in Python.

Output:

Hangup (SIGHUP)
Traceback (most recent call last):
  File "Solution.py", line 3, in <module>
    print(float(a))
ValueError: could not convert string to float: '67 . 89'

Python, a versatile and powerful programming language, is widely used for data manipulation and analysis. However, developers often encounter challenges, one of which is the “Cannot Convert String To Float” error. This error occurs when attempting to convert a string to a float, but the string’s content is incompatible with the float data type. In this article, we will delve into the reasons behind this error and provide practical solutions to overcome it.

What is “Cannot Convert String To Float” In Python?

The “Cannot Convert String to Float” error in Python typically occurs when attempting to convert a string to a float data type, but the string content is not a valid numeric representation. This error signals that the string contains non-numeric characters, making it impossible for Python to perform the conversion.

ValueError: could not convert string to float: '123.45abc'