Question

Python 3

A simple way to encrypt a file is to change all characters following a certain encoding rule. In this question, you need to move all letters to next letter. e.g. 'a'->'b', 'b'->'c', ..., 'z'->'a', 'A'->'B', 'B'->'C', ..., 'Z'->'A'. For all digits, you need to also move them to the next number. e.g. '0'->'1', '1'->'2', ..., '9'->'0'. All the other symbols should not be changed.

1. Write a function encrypt with the following requirements:

• the function takes a string argument, which is a file name.
• read the csv file.
• replace all characters uisng the rule above.
• write the content to a new file named "encrypted.csv".

2. Call the function with the file name "business-price-indexes-june-2020-quarter-csv-corrected.csv"

--2020-10-16 19:32:31-- https://www.stats.govt.nz/assets/Uploads/Business-price-indexes/Business-price-indexes-June-2020-quarter/Download-data/business-price-indexes-june-2020-quarter-csv-corrected.csv Resolving www.stats.govt.nz (www.stats.govt.nz)... 45.60.11.104 Connecting to www.stats.govt.nz (www.stats.govt.nz)|45.60.11.104|:443... connected. HTTP request sent, awaiting response... 200 OK Length: 11924606 (11M) [text/csv] Saving to: ‘business-price-indexes-june-2020-quarter-csv-corrected.csv’ business-price-inde 100%[===================>] 11.37M 4.56MB/s in 2.5s 2020-10-16 19:32:34 (4.56 MB/s) - ‘business-price-indexes-june-2020-quarter-csv-corrected.csv’ saved [11924606/11924606]

Answer 1

I have added the comments at every line for your understaning and also attaching the screenshots below for clarification.

for test sample i have used input.csv file as input and output_1.csv file as output you can change those names as per your requirement.

#importing the writer and reader libraries for csv file in python
from csv import writer
from csv import reader
# importing the module called csv which will be used  
import csv 

#for manpulating the alphabets during encryption we used this lib
from string import ascii_letters


#Encryption method as per your requirement
def Encrypt(Input_csv_filename):
  # we will open the input_file in read mode and our required output_file in write mode
  with open(Input_csv_filename, 'r') as reading_obj, \
          open('output_1.csv', 'w', newline='') as writing_obj:
      # we are creating a csv.reader_1 object from the given input file object which will be used to read
      csv_reader_1 = reader(reading_obj)
      # we are creating a csv.writer_2 object from the desired output file object which will be used to write
      csv_writer_2 = writer(writing_obj)
      # we are reading each row of the input of the given csv file as list
      for row in csv_reader_1:
        # we are parsing each column of a row 
        for col in row: 
          #two temporary strings to store 
          str_temp = col
          str_temp_2=''
          #replacing logic comes here as per your requirement
          for c in str_temp:
            if c == 'z':
              str_temp_2 += 'a'
            elif c == 'Z':
              str_temp_2 += 'A'
            elif ((ord(c) == 57)):
              str_temp_2 += '0'
            elif ((ord(c) >= 48) and (ord(c) < 57)):
              str_temp_2 += chr((ord(c)+1))
            elif c in ascii_letters:
              str_temp_2=str_temp_2+ascii_letters[(ascii_letters.index(c)+1)%len(ascii_letters)]
            else:
              str_temp_2+=c
          col=str_temp_2
          
      #priniting in the console output just for your understanding
        print(col)
        csv_writer_2.writerow([col])
    
Encrypt("input.csv")

output: (in console)

input file :

output file: