Change string in list to floats

thereiswaldo 0
Viewed 32

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?

string list python
1 Answers

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)
usertM450
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