Question

我正在尝试使用以下格式"a b c d e f g h"读取文本文件。我拿了一个新的空列表word = []

我的代码是：

f = open("letters.txt")

word = []

for line in f:
    line = line.split(" ")
    word.append(line)
print(word)

然而，它给了我一个这样的列表列表：

[['a', 'b', 'c', 'd', 'e', 'f']]

但我想把它放在一个列表中呢？

例如：

['a', 'b', 'c']

Answer 1

试试这个，

word = open("letters.txt").read().split()

<强>结果

['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h']

Answer 2

您可以改为打印您的行。

f = open("letters.txt")

for line in f:
    line = line.split(" ")
print line

Answer 3

@ Rahul的回答是正确的。但这应该有助于您了解何时不使用append

append(x)将x添加为列表末尾的新元素。 <{1}} x的作用并不重要。

extend

Answer 4

您应该知道每行代码中每个变量中的数据。如果您不知道 - 打印它然后您就会知道。

这次我会帮你的;）

f = open("letters.txt")
# f is an open file object. BTW, you never close it.
# Consider: with open("letters.txt", "rt") as f:

word = []
# 'word' is a list. That is strange, why not 'words = []'?

for line in f:
    # 'line' is a string. Fine.

    line = line.split(" ")

    # 'line' is no longer a string. Not fine.
    # This is perfectly valid code, but bad practice.
    # Don't change the type of data stored in a variable,
    # or you'll run into problems understanding what your code does.
    # Make a new variable, if you need one, e.g. 'line_words'.

    # Anyway, 'line' is now a list of words. Whatever.

    word.append(line)

    # This added a list (line) into another list (word).
    # Now it is a list of lists. There is your error.
    # 'word += line' would do what you wanted.

所有在一起：

with open("letters.txt", "rt") as f:
    words = []
    for line in f:
        words += line.split()

Answer 5

获得当前结果后，您可以尝试这样做：

import itertools
a = [["a","b"], ["c"]]
print list(itertools.chain.from_iterable(a))

Answer 6

split返回一个列表

使用sep作为分隔符字符串，返回字符串中的单词列表。

此列表在word末尾附加作为整体。这就是你得到一份清单

的原因

word [
    [ result of split of first line ]
    [ result of split of second line ]
    [ result of split of third line ]
    [ ... ]
]

如果您想添加列表中的每个元素，而不是将列表作为一个整体添加，您可以使用extend，即

for line in f:
    a = line.split(" ")
    word.extend(a)

虽然您可能希望在阅读多行时删除带有rstrip的尾随换行符

a = line.rstrip().split(" ")

或仅使用None作为字词分隔符

如果未指定sep或为None，则应用不同的拆分算法：连续空格的运行被视为单个分隔符，如果字符串具有前导或尾随，则结果将在开头或结尾处不包含空字符串空白。因此，将空字符串或仅由空格组成的字符串拆分为无分隔符将返回[]。

a = line.split()

我如何获得列表而不是列表列表？

6 个答案: