# Python check if variable is number

In Python, you can check if a variable is a number using various methods depending on the type of numbers you want to consider (integers, floats, complex numbers) and the version of Python you are using. Here are a few common methods:

1. Using the `isinstance()` function:

``````variable = 42  # Replace this with your variable

if isinstance(variable, (int, float, complex)):
print("Variable is a number.")
else:
print("Variable is not a number.")
``````

2. Using `type()` function:

``````variable = 42  # Replace this with your variable

if type(variable) in (int, float, complex):
print("Variable is a number.")
else:
print("Variable is not a number.")
``````

3. Using `isnumeric()` method (for strings):

``````variable = "42"  # Replace this with your variable

if variable.isnumeric():
print("Variable is a number.")
else:
print("Variable is not a number.")
``````

Note: the `isnumeric()` method only works for strings containing positive integers. If you need to handle more complex numeric cases, it’s better to use the `isinstance()` or `type()` functions to check for numeric types.

## Python checks if the variable is a number example

Python example that checks if a variable is a number:

``````def is_number(variable):
if isinstance(variable, (int, float, complex)):
return True
return False

# Test cases
num1 = 42
num2 = 3.14
num3 = 2 + 3j
str1 = "hello"
str2 = "42"

print(is_number(num1))  # Output: True
print(is_number(num2))  # Output: True
print(is_number(num3))  # Output: True
print(is_number(str1))  # Output: False
print(is_number(str2))  # Output: False
``````

Output:

In this example, we define a function `is_number()` that takes a variable as input and checks if it is an instance of any of the numeric types `(int, float, complex)`. The function returns `True` if the variable is a number and `False` otherwise.

Note: IDE: PyCharm 2021.3.3 (Community Edition)

Windows 10

Python 3.10.1

All Python Examples are in Python 3, so Maybe its different from python 2 or upgraded versions.