Examples of how to check if a python variable is a number (integer, float):
Check if a python variable is a number using isinstance
To check if a python variable is a number (int or float par example), a solution is to use isinstance:
x = 1.2isinstance(x, (int, float))
returns here
True
while
x = 'abcd'isinstance(x, (int, float))
returns
false
Case of a string variable
In the case of a string variable
x = '1'
the function isinstance
isinstance(x, (int, float))
will return
False
but to test if a string represents a number, a solution is to use isdigit, example
x = '1'x.isdigit()
returns
True
Filter a list to keep only numbers
Example of application, let's consider the following list:
l = [5, 3, 2, 'a', 9, 1, 4, 'NaN']
that can be filtered to keep only the numbers
que l'on peut filtrer pour ne garder que les nombres:
l = [i for i in l if isinstance(i, (int, float))]print(l)
returns
[5, 3, 2, 9, 1, 4]
