Search File And Find Exact Match And Print Line

Question

I searched around but i couldn t find any post to help me fix this problem  I found similar but i couldn t find any thing addressing this alone anyway   Here s the the problem I have  I m trying to have a python script search a text file  the text file has numbers in a list and every number corresponds to a line of text and if the raw input match s the exact number in the text file it prints that whole line of text  so far It prints any line containing the the number   Example of the problem  User types 20 then the output is every thing containing a 2 and a 0  so i get 220 foo 200 bar etc  How can i fix this so it just find  20   here is the code i have  num   raw input   Type Number      search   open  file txt   for line in search   if num in line    print line    Thanks

User · Answer

you should use regular expressions to find all you need:

import re
p = re.compile(r'(\d+)')  # a pattern for a number

for line in file :
    if num in p.findall(line) :
        print line

regular expression will return you all numbers in a line as a list, for example:

>>> re.compile(r'(\d+)').findall('123kh234hi56h9234hj29kjh290')
['123', '234', '56', '9234', '29', '290']

so you don't match '200' or '220' for '20'.

User · Answer

Build lists of matched lines - several flavors   def lines that equal line to match  fp       return  line for line in fp if line    line to match   def lines that contain string  fp       return  line for line in fp if string in line   def lines that start with string  fp       return  line for line in fp if line startswith string    def lines that end with string  fp       return  line for line in fp if line endswith string     Build generator of matched lines  memory efficient    def generate lines that equal string  fp       for line in fp          if line    string              yield line   Print all matching lines  find all matches first  then print them    with open  file txt    r   as fp      for line in lines that equal  my string   fp           print line   Print all matching lines  print them lazily  as we find them   with open  file txt    r   as fp      for line in generate lines that equal  my string   fp           print line   Generators  produced by yield  are your friends  especially with large files that don t fit into memory

User · Answer

It s very easy   numb   raw input  Input Line     fiIn   open  file txt   readlines   for lines in fiIn     if numb    lines 0         print lines

User · Answer

To check for an exact match you would use num    line  But line has an end-of-line character  n or  r n which will not be in num since raw input strips the trailing newline  So it may be convenient to remove all whitespace at the end of line with   line   line rstrip       with open  file txt   as search      for line in search          line   line rstrip      remove   n  at end of line         if num    line              print line

User · Answer

The check has to be like this   if num    line split   0     If file txt has a layout like this   1 foo 20 bar 30 20   We split up  1 foo  into   1    foo   and just use the first item  which is the number

User · Answer

num   raw input   Type Number      search   open  file txt   r   for line in search readlines        for digit in num            Check if any of the digits provided by the user are in the line          if digit in line              print line             continue

[python] Search File And Find Exact Match And Print Line?

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