使用命令行参数（带或不带空格）将选定的文本行从一个文件复制到另一个文件

Question

I am trying to write a program in python which searches for user specified words in a txt file and copies the selected lines containing that word into another file.

Also the user will have an option to exclude any word.

(eg Suppose the user searches for the word "exception" and want to exclude the word "abc", then the code will only copy the lines which has "exception" in it but not "abc").

Now all the work will be done from the command prompt.

The input would be:

file.py test.txt(input file) test_mod.txt(output file) -e abc(exclude word denoted by -e)-s exception(search word denoted by -s) Now the user will have an option to enter multiple exclude words and multiple search words.

I have done the program using the argparse module and it runs. My problem is when it searches for the word(both for the exclude word and the search word), it does not consider spaces.Eg It will find the word "exception" in the word "abcexception". Now sometimes I need this feature sometimes I don't. Here's my code as of now.

import sys
import os
import argparse
import tempfile
import re

def main(): #main method

 try:

  parser = argparse.ArgumentParser(description='Copies selected lines from files') #Defining the parser
  parser.add_argument('input_file')  #Adds the command line arguments to be given 
  parser.add_argument('output_file')
  parser.add_argument('-e',action="append")
  parser.add_argument('-s',action="append")
  args = parser.parse_args() #Parses the Arguments
  user_input1 = (args.e)    #takes the word which is to be excluded.
  user_input2 = (args.s)    #takes the word which is to be included.

  def include_exclude(input_file, output_file, exclusion_list=[], inclusion_list=[]):  #Function which actually does the file writing and also handles exceptions
      if input_file == output_file: 
          sys.exit("ERROR! Two file names cannot be the same.")
      else:
          try: 
              found_s = False  #These 3 boolean variables will be used later to handle different exceptions.
              found_e = False
              found_e1 = True
              with open(output_file, 'w') as fo:  #opens the output file
                  with open(input_file, 'r') as fi: #opens the input file
                       for line in fi:     #reads all the line in the input file
                           if user_input2 != None:


                               inclusion_words_in_line = map(lambda x: x in line, inclusion_list)#Mapping the inclusion and the exclusion list in a new list in the namespace  
                               if user_input1 != None and user_input2 != None:                   #This list is defined as a single variable as condition operators cannot be applied to lists
                                  exclusion_words_in_line = map(lambda x: x in line, exclusion_list)
                                  if any(inclusion_words_in_line) and not any(exclusion_words_in_line): #Main argument which includes the search word and excludes the exclusion words

                                      fo.write(line)  #writes in the output file
                                      found_s = True

                               elif user_input1 == None and user_input2 != None: #This portion executes if no exclude word is given,only the search word    
                                   if any(inclusion_words_in_line):
                                       fo.write(line)
                                       found_e = True
                                       found_s = True
                                       found_e1 = False

                       if user_input2 == None and user_input1 != None:       #No search word entered   

                           print("No search word entered.")

                       if not found_s and found_e:             #If the search word is not found                        
                           print("The search word couldn't be found.")
                           fo.close()
                           os.remove(output_file)

                       elif not found_e and not found_s:      #If both are not found                        
                           print("\nNOTE: \nCopy error.")
                           fo.close()
                           os.remove(output_file)

                       elif not found_e1:               #If only the search word is entered                              
                           print("\nNOTE: \nThe exclusion word was not entered! \nWriting only the lines containing search words")

          except IOError:
              print("IO error or wrong file name.")
              fo.close()
              os.remove(output_file)
  if user_input1 != user_input2 :  #this part prevents the output file creation if someone inputs 2 same words creating an anomaly.
         include_exclude(args.input_file, args.output_file, user_input1, user_input2);


  if user_input1 == user_input2 :  #This part prevents the program from running further if both of the words are same
         sys.exit('\nERROR!!\nThe word to be excluded and the word to be included cannot be the same.') 


 except SystemExit as e:                       #Exception handles sys.exit()
       sys.exit(e)



if __name__ == '__main__':
  main()

How can I include two more arguments in THIS program as let's say: -ew and -sw to search for the whole words only along with -e and -s which searches for the words even if there are not any spaces? So in total there would be 4 arguments.(-e, -s, -ew, -sw)

Answer 1

One option is to define a -w argument

parser.add_argument('-w', action='store_true')

This would set a args.w boolean. -we ... would be the same as -w -e ... . -ew wouldn't work because -e expects an argument, while -w does not. But this args.w is a global switch.

To control each search word separately I'd suggest argument names like --we , --ws in addition to your -e and -s . Ideally a single dash goes with a single letter, double dash with longer names. Or use -E and -S . Whether argparse enforces such a rule or not, your users will appreciate clear simple rules. In any case you will end up with 4 lists of words.

You don't need () in user_input1 = (args.e) . args.e is already a list, since the action is append . An alternative is nargs='+' , allowing you to enter -e word1 word2 -s word3 ... . + with append might also work, though args.e might be a list of lists, which you would then have to flatten.