delete from pattern to pattern if it contains match
Peter Otten
__peter__ at web.de
Fri Apr 22 05:24:06 EDT 2016
harirammanohar at gmail.com wrote:
> On Thursday, April 21, 2016 at 7:03:00 PM UTC+5:30, Jussi Piitulainen
> wrote:
>> harirammanohar at gmail.com writes:
>>
>> > On Monday, April 18, 2016 at 12:38:03 PM UTC+5:30,
>> > hariram... at gmail.com wrote:
>> >> HI All,
>> >>
>> >> can you help me out in doing below.
>> >>
>> >> file:
>> >> <start>
>> >> guava
>> >> fruit
>> >> <end>
>> >> <start>
>> >> mango
>> >> fruit
>> >> <end>
>> >> <start>
>> >> orange
>> >> fruit
>> >> <end>
>> >>
>> >> need to delete from start to end if it contains mango in a file...
>> >>
>> >> output should be:
>> >>
>> >> <start>
>> >> guava
>> >> fruit
>> >> <end>
>> >> <start>
>> >> orange
>> >> fruit
>> >> <end>
>> >>
>> >> Thank you
>> >
>> > any one can guide me ? why xml tree parsing is not working if i have
>> > root.tag and root.attrib as mentioned in earlier post...
>>
>> Assuming the real consists of lines between a start marker and end
>> marker, a winning plan is to collect a group of lines, deal with it, and
>> move on.
>>
>> The following code implements something close to the plan. You need to
>> adapt it a bit to have your own source of lines and to restore the end
>> marker in the output and to account for your real use case and for
>> differences in taste and judgment. - The plan is as described above, but
>> there are many ways to implement it.
>>
>> from io import StringIO
>>
>> text = '''\
>> <start>
>> guava
>> fruit
>> <end>
>> <start>
>> mango
>> fruit
>> <end>
>> <start>
>> orange
>> fruit
>> <end>
>> '''
>>
>> def records(source):
>> current = []
>> for line in source:
>> if line.startswith('<end>'):
>> yield current
>> current = []
>> else:
>> current.append(line)
>>
>> def hasmango(record):
>> return any('mango' in it for it in record)
>>
>> for record in records(StringIO(text)):
>> hasmango(record) or print(*record)
>
> Hi,
>
> not working....this is the output i am getting...
>
> \
This means that the line
>> text = '''\
has trailing whitespace in your copy of the script.
> <start>
> guava
> fruit
>
> <start>
> orange
> fruit
Jussi forgot to add the "<end>..." line to the group. To fix this change the
generator to
def records(source):
current = []
for line in source:
current.append(line)
if line.startswith('<end>'):
yield current
current = []
>> hasmango(record) or print(*record)
The
print(*record)
inserts spaces between record entries (i. e. at the beginning of all lines
except the first) and adds a trailing newline. You can avoid this by
specifying the delimiters explicitly:
if not hasmango(record):
print(*record, sep="", end="")
Even with these changes code still looks somewhat brittle...
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