Question

我正在运行以下循环：

months = ['January', 'February', 'March', 'April', 'May', 'June', 'July', 'August', 'September', 'October', 'Novemeber', 'December']

for i in range(len(sections)): 

    if (' tax ' in sections[i]
    or ' Tax ' in sections[i]):

        pat=re.compile("|".join([r"\b{}\b".format(m) for m in months]), re.M)
        month = pat.search("\n".join(sections[i].splitlines()[0:6]))
        print(month)

我想为值range(len(sections))运行循环，除了其中一些。例如，除了值12,13,55,67和70之外，范围内涵盖的所有值。

我知道我可以将范围分成几部分，但我很乐意只通过编写数字来实现。有什么建议吗？

Answer 1

使用enumerate

for index, element in enumerate(some_list):
    if index in range(1, 20):
        print("Element: {0} with index {1} in first range".format(element, index))
    elif index in [82, 111]:
        print("Element: {0} with index {1} in second range".format(element, index))

Answer 2

您可以使用ifilterfalse中的itertools功能，如下所示：

from itertools import ifilterfalse

# Build an example list of sections, e.g. sections = [' tax 1', ' tax 2' ....., ' tax 79']
sections = [" tax {}".format(i) for i in range(1, 80)]

# Entries to skip over
skip = [12, 13, 55, 67, 70]

for index, value in ifilterfalse(lambda (i, v): i in skip, enumerate(sections, start=1)):
    print value

这可以用于仅迭代所需的条目，跳过您不需要的值。它将显示以下内容：

 tax 1
 tax 2
 tax 3
 tax 4
 tax 5
 tax 6
 tax 7
 tax 8
 tax 9
 tax 10
 tax 11
 tax 14
 tax 15
 tax 16
 tax 17
 tax 18
 tax 19
 tax 20
 tax 21
 tax 22
 tax 23
 tax 24
 tax 25
 tax 26
 tax 27
 tax 28
 tax 29
 tax 30
 tax 31
 tax 32
 tax 33
 tax 34
 tax 35
 tax 36
 tax 37
 tax 38
 tax 39
 tax 40
 tax 41
 tax 42
 tax 43
 tax 44
 tax 45
 tax 46
 tax 47
 tax 48
 tax 49
 tax 50
 tax 51
 tax 52
 tax 53
 tax 54
 tax 56
 tax 57
 tax 58
 tax 59
 tax 60
 tax 61
 tax 62
 tax 63
 tax 64
 tax 65
 tax 66
 tax 68
 tax 69
 tax 71
 tax 72
 tax 73
 tax 74
 tax 75
 tax 76
 tax 77
 tax 78
 tax 79

或者仅使用enumerate和in，如下所示：

# Build an example list of sections, e.g. sections = [' tax 1', ' tax 2' ..... ' tax 79']
sections = [" tax {}".format(i) for i in range(1, 80)]

for index, value in enumerate(sections, start=1):
    if index not in [12, 13, 55, 67, 70]:
        print value

使用Python循环除了某些值

2 个答案: