python - 尝试理解 .strip

Question

我有一个名为 input.py 的文件，其中包含以下内容:

#This is a file of categories
Animals:    cat, dog, frog, cheetah, tiger
Items:      desk, chair, bus, cups, pencil

Technology: cellphone, TV, laptop, wifi-router
    #That's the end of the file

我想过滤掉所有空白行和以#开头的行以生成output.py:

Animals:    cat, dog, frog, cheetah, tiger
Items:      desk, chair, bus, cups, pencil
Technology: cellphone, TV, laptop, wifi-router

我的代码是

with open('input.py', 'r') as infile, open('output.py', 'w') as outfile:
    for line in infile:
        if line[0].strip('') == '#' or line == '\n':
            pass
        else:
            outfile.write(line)

但它不会删除以制表符开头的行。我尝试将 .strip('') 替换为 .strip('\t') 但得到相同的输出:

Animals:    cat, dog, frog, cheetah, tiger
Items:      desk, chair, bus, cups, pencil
Technology: cellphone, TV, laptop, wifi-router
    #That's the end of the file

为什么 .strip('') 或 .strip('\t') 没有剥离标签？

Answer 1

Strip 方法只能删除字符串开头或结尾的字符。尝试使用替换。

>>> line = "Animals:    cat, dog, frog, cheetah, tiger"
>>> line.replace('\t', ' ')
'Animals: cat, dog, frog, cheetah, tiger'