Question

The code below is supposed to lookup first column (key) from a file Dict_file and replace the first column of another file fr, with the value of the key found from dict_file. But it keeps the dict_file as an updated dictionary for future lookups.

Every time the code is run, it initializes a dictionary from that dict_file file. If it finds a new email address from another file, it adds it to the bottom of the dict_file.

It should work fine according to my understanding because if it doesn’t find an @ symbol it assigns looking_for the value of “[e-mail]”.. [e-mail] should be appended to the bottom of dict_file.

But for some reason, I keep getting new lines and blank lines appended along with other new emails at the end of the dict_file. I can’t be writing blanks and newlines to the end of the dict_file.

Why is this happening? Whats wrong in the code below, my brain is about to explode! Any help will be greatly appreciated!

#!/usr/bin/python

import sys

d = {}
line_list=[]
alist=[]

f = open(sys.argv[3], 'r') # Map file

for line in f:
    alist = line.split()
    key = alist[0]
    value = alist[1]
    d[str(key)] = str(value)
    alist=[]
f.close()

fr = open(sys.argv[1], 'r') # source file

fw = open(sys.argv[2]+"/masked_"+sys.argv[1], 'w') # target file

for line in fr:
    columns = line.split("|")
    looking_for = columns[0] # this is what we need to search
    if looking_for in d:
        # by default, iterating over a dictionary will return keys
        if not looking_for.find("@"):
            looking_for == "[e-mail]"
            new_line = d[looking_for]+'|'+'|'.join(columns[1:])
            line_list.append(new_line)
        else:
            new_line = d[looking_for]+'|'+'|'.join(columns[1:])
            line_list.append(new_line)
    else:
        new_idx = str(len(d)+1)
        d[looking_for] = new_idx
        kv = open(sys.argv[3], 'a')
        kv.write("\n"+looking_for+" "+new_idx)
        kv.close()
        new_line = d[looking_for]+'|'+'|'.join(columns[1:])
        line_list.append(new_line)
fw.writelines(line_list)

Here is the dict_file:

[e-mail]    223
[e-mail] 224
[e-mail]  225
[e-mail]  226
[e-mail] 227

Here is the fr file that gets the first column turned into the id from the dict_file lookup:

[e-mail]|12|1|GDSP
[e-mail]|13|7|GDFP
[e-mail]|12|1|GDOP
[e-mail]|132|1|GUIP
MONITOR|132|1|GUIP
    |132|1|GUIP
00 |12|34|GUILIGAN

Answer 1

Firstly, you need to ignore blanks in your initial dictionary read, otherwise you will get an index out of range error when you run this script again. Do the same when you read via the fr object to avoid entering nulls. Wrap your email check condition further out for greater scope. Do a simple check for the “@” using the find method. And you’re good to go.

Try the below. This should work:

#!/usr/bin/python

import sys

d = {}
line_list=[]
alist=[]
f = open(sys.argv[3], 'r') # Persisted Dictionary File

for line in f:
    line = line.strip()
    if line =="":
        continue
    alist = line.split()
    key = alist[0]
    value = alist[1]
    d[str(key)] = str(value)
    alist=[]
f.close()

fr = open(sys.argv[1], 'r') # source file
fw = open(sys.argv[2]+"/masked_"+sys.argv[1], 'w') # Target Directory Location

for line in fr:
    line = line.strip()
    if line == "":
        continue
    columns = line.strip().split('|')
    if columns[0].find("@") > 1:
        looking_for = columns[0] # this is what we need to search
    else:
        looking_for = "[e-mail]"
    if looking_for in d:
        # by default, iterating over a dictionary will return keys
            new_line = d[looking_for]+'|'+'|'.join(columns[1:])
            line_list.append(new_line)
    else:
        new_idx = str(len(d)+1)
        d[looking_for] = new_idx
        kv = open(sys.argv[3], 'a')
        kv.write(looking_for+" "+new_idx+'\n')
        kv.close()
        new_line = d[looking_for]+'|'+'|'.join(columns[1:])
        line_list.append(new_line)
fw.writelines(line_list)