python converting strings in list to ints and floats

问题

If I were to have the following list:

lst = ['3', '7', 'foo', '2.6', 'bar', '8.9']

how would I convert all possible items into either ints or floats accordingly, to get

lst = [3, 7, 'foo', 2.6, 'bar', 8.9]

thanks in advance.

回答1:

Loop over each item and make an attempt to convert. If the conversion fail then you know it's not convertible.

def tryconvert(s):
    try:
        return int(s)
    except ValueError:
        try:
            return float(s)
        except ValueError:
            return s

lst = ['3', '7', 'foo', '2.6', 'bar', '8.9']
newlst = [tryconvert(i) for i in lst]
print(newlst)

Output:

[3, 7, 'foo', 2.6, 'bar', 8.9]

回答2:

Try something like this :

lst = ['3', '7', 'foo', '2.6', 'bar', '8.9']

for j,i in enumerate(lst):
    if i.isdigit():
        lst[j]=int(i)
    elif '.' in i:
        lst[j]=float(i)

output:

[3, 7, 'foo', 2.6, 'bar', 8.9]

来源：https://stackoverflow.com/questions/48441382/python-converting-strings-in-list-to-ints-and-floats