从列表中的字符串中提取第n行文本-Python

Question

I have a list that consists of 149 text strings. From each string, I would like to extract the 2nd and 7th lines of text. I'd like the results of each line to be put in a separate list.

I've tried (just for one line):

text = []  
for string in list:
  x = string.splitlines()[2]
  text.append(x)

But I get the message "IndexError: list index out of range". I thought maybe I needed to do:

text = []  
for string in list:
  x = [string].splitlines()[2]
  text.append(x)

But that gave me the message "AttributeError: 'list' object has no attribute 'splitlines'"

I'm using Python 3.6. Any ideas? Thanks for your help!

Answer 1

string.splitlines is the correct function to split the lines of each string, and if it gives an IndexError for index 2 (note: this is the 3rd line) then that means that there are fewer than three lines. This is probably the code you're looking for:

line2_results = []
line7_results = []
for str in list:
    lines = str.splitlines()
    if len(lines) >= 2:
        line2_results.append(lines[1])
        if len(lines) >= 7:
            line7_results.append(lines[6])