Python在找到特定行时添加行

Question

I'm having trouble writing a line to txt file when when a specific line is found.

Here is my txt file:

Wed Oct  7 09:00:01

station: 01

station: 02

station: 03



Wed Oct  7 09:05:01

station: 06

station: 05
 
station: 06

I need the output txt file look like this:

Wed Oct  7 09:00:01

Time: Wed Oct  7 09:00:01

station: 01

Time: Wed Oct  7 09:00:01

station: 02

Time: Wed Oct  7 09:00:01

station: 02


Wed Oct  7 09:05:01

Time: Wed Oct  7 09:05:01

station: 04

Time: Wed Oct  7 09:05:01

station: 05

Time: Wed Oct  7 09:05:01

station: 05

When a date is found, it adds a new line with that date before a station. If it met a 2nd date, it adds that new date to the next station

Here is my code:

date1 = 'Wed Oct 7 09:00:01'
date2 = 'Wed Oct 7 09:05:01'
with open('text.txt') as f_input, open('text2.txt', 'w', newline='') as f_output:
    for line in f_input:
        if date1 in line:
            if line.startswith('station'):
                line = 'Time: ' + date1 + line
        if date2 in line:
            if line.startswith('station'):
                line = 'TIME: ' + date2 + line
    f_output.write(line)

When I run the code, the result is only "station 06". Please let me know how to fix this. Thank you.

Answer 1

您只向文件写入一行，检查代码中最后一行的缩进，它不在 for 循环内。

Answer 2

This script should get the output you expect. There is an indentation error in your code and the if condition is not correct. Compare the code and you will understand.

import re

date = None
date_regex = "[a-z]{3}[\ ]+[a-z]{3}[\ ]+[0-9]{1,2}[\ ]+[0-9]{1,2}\:[0-9]{1,2}\:[0-9]{1,2}"
with open('text.txt') as f_input, open('text2.txt', 'w', newline='') as f_output:
    for line in f_input:
        date_match = re.match(date_regex, line, re.I)
        if date_match:
            date = date_match.group()
        if date and date not in line and line.startswith('station'):
            line = 'Time: ' + date + '\n\n' + line
        f_output.write(line)

Answer 3

I have removed the file part for obvious reasons.

lines = """Wed Oct  7 09:00:01
station: 01
station: 02
station: 03
Wed Oct  7 09:05:01
station: 06
station: 05 
station: 06""".split("\n")

pattern = """^(Mon|Tue|Wed|Thu|Fri|Sat|Sun)\s(Jan|Feb|Mar|Apr|May|Jun|Jul|Aug|Sep|Oct|Nov|Dec)\s*\d\s*\d{2}[\:]\d{2}[\:]\d{2}"""


output = ""
last_match = ""
for line in lines:
    message = line + "\n"
    if re.match(pattern, line):
        last_match = line 
    else:
        if last_match:
            message = "Time: " + last_match + "\n" + message
    output = output + message

print(output.rstrip("\n")) # if you must remove the last EOL        
        

# output
Wed Oct  7 09:00:01
Time: Wed Oct  7 09:00:01
station: 01
Time: Wed Oct  7 09:00:01
station: 02
Time: Wed Oct  7 09:00:01
station: 03
Wed Oct  7 09:05:01
Time: Wed Oct  7 09:05:01
station: 06
Time: Wed Oct  7 09:05:01
station: 05 
Time: Wed Oct  7 09:05:01
station: 06