如何阅读其中一些内容有换行符的文本文件？

Question

我有这种形式的文本文件：

06/01/2016, 10:40 pm - abcde 
07/01/2016, 12:04 pm - abcde 
07/01/2016, 12:05 pm - abcde 
07/01/2016, 12:05 pm - abcde 
07/01/2016, 6:14 pm - abcde 

fghe 
07/01/2016, 6:20 pm - abcde 
07/01/2016, 7:58 pm - abcde 

fghe 

ijkl 
07/01/2016, 7:58 pm - abcde 

可以看到，每一行由换行符分隔，但有些行的内容在他们换行符。所以，简单地按行分隔并不能正确解析每一行。

举例来说，对于第5项，我想我的输出是 07/01/2016, 6:14 pm - abcde fghe

这里是我当前的代码：

with open('file.txt', 'r') as text_file: 
data = [] 
for line in text_file: 
    row = line.strip() 
    data.append(row) 

Answer 1

鉴于你例如输入，你可以用一个regex以正前瞻：

pat=re.compile(r'^(\d\d\/\d\d\/\d\d\d\d.*?)(?=^^\d\d\/\d\d\/\d\d\d\d|\Z)', re.S | re.M) 

with open (fn) as f: 
    pprint([m.group(1) for m in pat.finditer(f.read())])  

打印：

['06/01/2016, 10:40 pm - abcde\n', 
'07/01/2016, 12:04 pm - abcde\n', 
'07/01/2016, 12:05 pm - abcde\n', 
'07/01/2016, 12:05 pm - abcde\n', 
'07/01/2016, 6:14 pm - abcde\n\nfghe\n', 
'07/01/2016, 6:20 pm - abcde\n', 
'07/01/2016, 7:58 pm - abcde\n\nfghe\n\nijkl\n', 
'07/01/2016, 7:58 pm - abcde\n'] 

---

随着Dropbox的例子，打印：

['11/11/2015, 3:16 pm - IK: 12\n', 
'13/11/2015, 12:10 pm - IK: Hi.\n\nBut this is not about me.\n\nA donation, however small, will go a long way.\n\nThank you.\n', 
'13/11/2015, 12:11 pm - IK: Boo\n', 
'15/11/2015, 8:36 pm - IR: Root\n', 
'15/11/2015, 8:36 pm - IR: LaTeX?\n', 
'15/11/2015, 8:43 pm - IK: Ws\n'] 

如果你想删除\n在被捕获的内容中，只需将m.group(1).strip().replace('\n', '')添加到上面的列表理解中即可。

---

说明正则表达式：

^(\d\d\/\d\d\/\d\d\d\d.*?)(?=^^\d\d\/\d\d\/\d\d\d\d|\Z) 

^              start of line 
    ^^^^ ^         pattern for a date 
        ^        capture the rest... 
         ^       until (look ahead) 
            ^^^   another date 
               ^ or 
                ^end of string 

Answer 2

你可以使用正则表达式（使用re模块）来检查日期是这样的：

import re 
with open('file.txt', 'r') as text_file: 
    data = [] 
    for line in text_file: 
    row = line.strip() 
    if re.match(r'\d{2}/\d{2}/\d{4}.*'): 
     data.append(row) # date: new record 
    else: 
     data[-1] += '\n' + row # no date: append to last record 

# '\d{2}': two digits 
# '.*': any character, zero or more times 

Answer 3

考虑到','只能显示为分隔符，我们m AY检查线路有一个逗号，如果没有它串联到最后一行：

data = [] 

with open('file.txt', 'r') as text_file: 
    for line in text_file: 
     row = line.strip() 
     if ',' not in row: 
      data[-1] += '\n' + row 
     else: 
      data.append(row) 

Answer 4

的长度简单的测试：

#!python3 
#coding=utf-8 

data = """06/01/2016, 10:40 pm - abcde 
07/01/2016, 12:04 pm - abcde 
07/01/2016, 12:05 pm - abcde 
07/01/2016, 12:05 pm - abcde 
07/01/2016, 6:14 pm - abcde 

fghe 
07/01/2016, 6:20 pm - abcde 
07/01/2016, 7:58 pm - abcde 

fghe 

ijkl 
07/01/2016, 7:58 pm - abcde""" 

lines = data.split("\n") 
out = [] 
for l in lines: 
    c = l.strip() 
    if c: 
     if len(c) < 10: 
      out[-1] += c 
     else: 
      out.append(c) 
    #skip empty 

for o in out: 
    print(o) 

结果：

06/01/2016, 10:40 pm - abcde 
07/01/2016, 12:04 pm - abcde 
07/01/2016, 12:05 pm - abcde 
07/01/2016, 12:05 pm - abcde 
07/01/2016, 6:14 pm - abcdefghe 
07/01/2016, 6:20 pm - abcde 
07/01/2016, 7:58 pm - abcdefgheijkl 
07/01/2016, 7:58 pm - abcde 

不包含数据中的换行符！

---

但这一个衬里的正则表达式应该这样做（在断行分割后按数字），至少对样品数据（断裂时的数据包含换行符后按数字）：

#!python3 
#coding=utf-8 

text_file = """06/01/2016, 10:40 pm - abcde 
07/01/2016, 12:04 pm - abcde 
07/01/2016, 12:05 pm - abcde 
07/01/2016, 12:05 pm - abcde 
07/01/2016, 6:14 pm - abcde 

fghe 
07/01/2016, 6:20 pm - abcde 
07/01/2016, 7:58 pm - abcde 

fghe 

ijkl 
07/01/2016, 7:58 pm - abcde""" 

import re 
data = re.split("\n(?=\d)", text_file) 

print(data) 

for d in data: 
    print(d) 

输出：

['06/01/2016, 10:40 pm - abcde', '07/01/2016, 12:04 pm - abcde', '07/01/2016, 12:05 pm - abcde', '07/01/2016, 12:05 pm - abcde', '07/01/2016, 6:14 pm - abcde\n\ 
nfghe', '07/01/2016, 6:20 pm - abcde', '07/01/2016, 7:58 pm - abcde\n\nfghe\n\nijkl', '07/01/2016, 7:58 pm - abcde'] 
06/01/2016, 10:40 pm - abcde 
07/01/2016, 12:04 pm - abcde 
07/01/2016, 12:05 pm - abcde 
07/01/2016, 12:05 pm - abcde 
07/01/2016, 6:14 pm - abcde 

fghe 
07/01/2016, 6:20 pm - abcde 
07/01/2016, 7:58 pm - abcde 

fghe 

ijkl 
07/01/2016, 7:58 pm - abcde 

---

（固定用先行）