python 正则表达式在新行后删除

Question

I'm trying to drop everything once it sees a CRLF ( \r\n ) line break sequence after the word Total_Cases .

Input 1:

Some text\r\nTotal_Cases      -     1     -     1\r\n**Please

Required output 1:

Some text\r\nTotal_Cases      -     1     -     1`

Input 2:

Some text\r\nTotal_Cases     3      1     -     -     -     4\r\n  9 of 15\r\n

Required output:

Some text\r\nTotal_Cases     3      1     -     -     -     4

Code used:

re.sub(r'(Total_Cases[\n]).*', r'\1', test1, flags=re.S).rstrip()
re.sub(r'(Total_Cases[\r\n]).*', r'\1', test1, flags=re.S).rstrip()

Neither seems to be working as expected.

Answer 1

You may use

re.sub(r'(Total_Cases.*?)[\r\n].*', r'\1', test1, flags=re.S).rstrip()

See the Python demo and the regex demo .

Details

• (Total_Cases.*?) - Group 1 ( \1 from the replacement pattern refers to this value): Total_Cases and then any 0 or more chars, as few as possible
• [\r\n] - a CR or LF symbol
• .* - any chars up to the string end.

A non-regex approach : iterate over the lines and once the match if found on a line, stop appending lines to the resulting list:

test1 = "More necessary\r\nlines\r\nhere\r\nTotal_Cases - 1 - 1\r\n**Please"
search = "Total_Cases"
lines = test1.splitlines()
results = []
for line in lines:
    results.append(line)
    if search in line:
        break
print ( "\n".join(results) )

Output:

More necessary
lines
here
Total_Cases - 1 - 1

Answer 2

Try this for each string you have as input:

input1 =  'Total_Cases - 1 - 1\r\n**Please'
input1.splitlines()[0]

Answer 3

You can try this:

x = 'Total_Cases - 1 - 1\r\n**Please'

index = x.index('\r\n')

if index:
    print(x[:index])

else:
    print(x)