python - How to remove strings that contain letters from a list? -

i have list containing strings both letters, characters , and numbers:

list = ['hello', '2u:', '-224.3', '45.1', 'sa 2'] 

i want keep numbers in list , convert them float values. how can that? want list this:

list = ['-224.3'. '45.1'] 

the list created, when serial.readline() arduino, gives me string comprised of commands , data points. looked this:

'hello,2u:,-224.3,45.1,sa 2' 

i did list.split(delimiter=',') , wanted have data points future calculations.

probably best way see whether string can cast float try cast it.

res = [] x in lst:     try:         res.append(float(x))     except valueerror:         pass 

afterwards, res [-224.3, 45.1]

you could make list comprehension, [float(x) x in lst if is_float(x)], need function is_float same thing: try cast float , return true, otherwise return false. if need once, loop shorter.