Category: python

Hi,

There was a issue on options that aggregate any other ones, like -A for my previous post

In my view the easiest way to solve it is by storing the options in a tuple.

Here is the snippet

run_options = []
try:
    opts, args = getopt.gnu_getopt(sys.argv[1:-1], 'AbeEnstTv', ['show-all', 'number-nonblank', 'show-ends', 'number', 'show-blank', 'squeeze-blank' 'show-tabs', 'show-nonprinting', 'help', 'version'])
except getopt.GetoptError:
     print("Something went wrong")
     sys.exit(2)
for opt, arg in opts:
    if opt in ('-A','--show-all'):
        run_options.append('E')
        run_options.append('T')
    elif opt in ('-b', '--number-nonblank'):
        run_options.append('b')
    elif opt in ('-n', '--number'):
        run_options.append('n')
    elif opt in ('-E', '--show-ends'):
        run_options.append('E')
    elif opt in ('-s', '--squeeze-blank'):
        run_options.append('s')
    elif opt in ('-T', '--show-tabs'):
        run_options.append('T')
 
final_run_options = tuple(run_options)
for element in final_run_options:
    if element == 'b':
        content_list = number_nonempty_lines(content_list)
    elif element == 'n':
        content_list = number_all_lines(content_list)   
    elif element == 'E':
        content_list = display_endline(content_list)
    elif element == 's':
        content_list = squeeze_blanks(content_list)
    elif element == 'T':
        content_list = show_tabs(content_list)

So basically, you store the actual cases in a list which you convert to a tuple to eliminate duplicates. Once you have the final case, you parse it and change the actual content option by option.

I didn’t have the time to test it but there is no big reason why it should’t work.

Cheers

Morning,

Since I am striving to find useful content to post more often, I took homework for a ‘cat’ written in Python.

It’s not elegant, and it’s not the best version but it works.

# -*- coding: utf-8 -*-
"""
Created on Wed Dec 25 10:28:39 2019
@author: Sorin
"""
import sys,getopt,os
if os.path.isabs(sys.argv[-1:][0]):
    FILENAME= sys.argv[-1:][0]
else:
    FILENAME = os.getcwd() + "\\" + sys.argv[-1:][0]

def read_content(filename):
    try:
        f = open(filename, "r+")
        content = f.read()
        f.close()
    except IOError as e:
            print("File could not be opened:", e)
            sys.exit(3)
    return content
    
def transform_content():
    content = read_content(FILENAME)
    content_list = content.split('\n')
    return content_list
def number_nonempty_lines(content_list):
    i = 0
    for line in content_list:
        if line != '':
            content_list[i] = str(i) + " " + line
        i = i + 1
    return content_list
def squeeze_blanks(content_list):   
    i = 0
    duplicate_index = []
    for line in content_list:
        if (line == "" or line == "$")  or (str.isdigit(line.split(' ')[0]) and (line.split(' ')[-1] == "" or line.split(' ')[-1] == "$")):
           duplicate_index.append(i+1)
        i = i + 1
    delete_index = []
    for j in range(len(duplicate_index) - 1):
        if  duplicate_index[j] + 1 == duplicate_index[j+1]:
            delete_index.append(duplicate_index[j])
    for element in delete_index:
        content_list.pop(element)
    return content_list    
        
def number_all_lines(content_list):
    i = 0
    for line in content_list:
        content_list[i] = str(i) + " " + line
        i = i + 1
    return content_list

def display_endline(content_list):
   return [line + "$" for line in content_list]

def show_tabs(content_list):
    print(content_list)
    content_list = [ line.replace('\t','^I') for line in content_list]
    return content_list

content_list =transform_content()
try:
    opts, args = getopt.gnu_getopt(sys.argv[1:-1], 'AbeEnstTv', ['show-all', 'number-nonblank', 'show-ends', 'number', 'show-blank', 'squeeze-blank' 'show-tabs', 'show-nonprinting', 'help', 'version'])
except getopt.GetoptError:
     print("Something went wrong")
     sys.exit(2)
for opt, arg in opts:
    if opt in ('-A','--show-all'):
        content_list = display_endline(content_list)
        content_list = show_tabs(content_list)
    elif opt in ('-b', '--number-nonblank'):
       content_list = number_nonempty_lines(content_list)
    elif opt in ('-n', '--number'):
       content_list = number_all_lines(content_list)
    elif opt in ('-E', '--show-ends'):
        content_list = display_endline(content_list)
    elif opt in ('-s', '--squeeze-blank'):
        content_list = squeeze_blanks(content_list)
    elif opt in ('-T', '--show-tabs'):
        content_list = show_tabs(content_list)
print('\n'.join(content_list))

Further improvements will be also posted. I must confess that there are still a couple of things to be fixed, like not running the same options twice, and the issue of putting it to work on very large files, but it will do in this form for now.

Cheers