python - python中的列表和文件

Question

我正在使用 python 中的 readlines 方法来获取所有数据行的列表。现在我不想访问该列表中的某些索引:

file = open('article.txt', 'r')
data = file.readlines()
print data.index(1)
Error: data isn't a list

怎么了？

Answer 1

我想你的意思是(如果你的目标是打印列表的第二个元素):

 print data[1]

data.index(value) 返回value的列表位置:

>>> data = ["a","b","c"]
>>> data[1]          # Which is the second element of data?
b
>>> data.index("a")  # Which is the position of the element "a"?
0
>>> data.index("d")  # Which is the position of the element "d"? --> not in list!
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ValueError: list.index(x): x not in list