file_manipulation_1 (Manipulating the File System)

Description

In this exercise, we will focus on the os module to manipulate the directory tree of our file system and we will practice some more with reading and writing files.

Tasks

Task 1

Define a function named show_data_list that prints the contents of the directory src/data/initial.

• Your result should look like this:

todos.txt
jobs.csv
bookmarks.txt
customers.csv

Task 2

To avoid manipulating the file system outside of our working folder you will define the constants ROOT and DATA_ROOT.

These constants will be used throughout the rest of the exercise.

Define a constant, named ROOT that points to the full path of your current script.

Now, define another constant, named DATA_ROOT that defines the full path of the initial directory, based on the ROOT.

In pseudocode:

ROOT = detect the current path of the script
DATA_ROOT = ROOT + src/data/initial

You are not allowed to type in the paths. The script should produce the correct answer if you clone this repository in a different location of your file system.

You are not allowed to concatenate strings or use string formatting. Only the methods from the os and os.path modules are allowed.

• Once defined, print them on the console. Your output should look similar to this(*):

/home/DCI/PythonCourse/Python-basics-io-os
/home/DCI/PythonCourse/Python-basics-io-os/src/data/initial

(*) The exact path will depend on where you cloned this repository and the type of Operating System used.

Task 3

Define a function named create_data_directories that takes a list of strings and creates a directory for each one (with the given name) in the directory src/data/initial.

The script will only create these directories if they do not exist. If they do, it will output a message saying The directory {directory} already exists.

Use the constant DATA_ROOT to make sure the function will not create directories outside the working directory.

Use the following list to call the function:

dirs = ["personal", "work"]

• After executing your script, the directory tree should look like this:

+ initial
  + personal
  + work
  - todos.txt
  - jobs.csv
  - bookmarks.txt
  - customers.csv

• Now, execute the script again, and you should see this message:

The directory personal already exists.
The directory work already exists.

Task 4

Now write another function named classify that takes a dictionary like this one:

{
    "directory_name": ["file_name_1", "file_name_2"]
}

The function should move each file to the appropriate directory.

Use the constant DATA_ROOT to make sure the function will not move the files outside the working directory.

Use the following dictionary to test it on the data:

categories = {
    "personal": ["todos.txt", "bookmarks.txt"],
    "work": ["customers.csv", "jobs.csv"]
}

• Once executed, the directory tree of the initial directory should look like this:

+ initial
  + personal
    - bookmarks.txt
    - todos.txt
  + work
    - customers.csv
    - jobs.csv

Task 5

Now you will produce a basic report about the pending jobs (those with a status different than done).

This report will be in the form of a CSV, it will be named pending_jobs.csv and will be placed in a new directory named reports in the work directory. The script should create this directory if it does not exist. If it does, it should continue silently.

The report should have the following fields:

• id: the id of the job.
• description: the description of the job.
• client: the name of the client.

Hints

• Remember that it is better to ask forgiveness, than asking permission.
• You will have to open 3 files: customers.csv and jobs.csv for reading, and pending_jobs.csv for writing.
• You may want to store first the data about customers in a list and then go through each line in the jobs.csv file to search for the customer name and filter those with a status different than done.

The pending_jobs.csv file should look like this:

id,description,client
2,Provide a report,Digital Inc.
3,Review GIT pull requests,Juniper Features

The directory tree now should look like this:

+ initial
  + personal
    - bookmarks.txt
    - todos.txt
  + work
    + reports
      - pending_jobs.csv
    - customers.csv
    - jobs.csv