如何在 Python 中转换`str.split()` 的元素？

Question

I have the following:

[line.split(' ') for line in [
        line.rstrip() for line in file.readlines()]]

which returns a list of list of strings. I know I could do the following to convert it to a list of list of integers:

    for row in tree:
        row[:] = map(int, row[:])

Can that be done inline as the lines are being processed?

Some sample data:

59
73 41
52 40 09
26 53 06 34
10 51 87 86 81

Answer 1

You could use

data = """
59
73 41
52 40 09
26 53 06 34
10 51 87 86 81
"""

result = [[int(x) for x in line.split()] for line in data.split("\n") if line]
print(result)

Which yields

[[59], [73, 41], [52, 40, 9], [26, 53, 6, 34], [10, 51, 87, 86, 81]]

---

Note that this only works if you only have integers.
To have some error management, you could use:

data = """
59 some junk here
73 41
52 40 09
26 53 06 34
10 51 87 86 81
"""

def makeint(line):
    for x in line.split():
        try:
            yield int(x)
        except ValueError:
            pass

result = [[x for x in makeint(line)] for line in data.split("\n") if line]
print(result)