Change string in list to floats-CodePudding

I have a list as follows:

pos = ['52.1,13.3','53.2,14.3',....,'55.3,16.4']

I want to change each string in the list to a float, such that I get the following:

pos = [52.1,13.3,53.2,14.3,....,55.3,16.4]

I am using the following loop:

b = []

for str in a:
    str = float(str)
    b.append(str)

print (b)

Which raises the following error

ValueError: could not convert string to float: '52.1,13.3'

How do I change the strings into separate floats in a new list?

CodePudding user response：

You have to split the strings at the comma and apply float to each of the entries. Then extend the list with those floating point values.

pos = ['52.1,13.3','53.2,14.3','55.3,16.4']

lst = []
for entry in pos:
    lst.extend(map(float, entry.split(',')))
print(lst)

This will give you [52.1, 13.3, 53.2, 14.3, 55.3, 16.4].

If you're unfamiliar with map you should learn how to use it. But nevertheless here's a version with a loop approach:

lst = []
for entry in pos:
    for value in entry.split(','):
        lst.append(float(value))
print(lst)