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Python Python for File Systems Manipulation Daily Backup

Posted by hamsternation
hamsternation
26,616 Points

Didn't find the right directory for year-month-day date?

The prompt: Create a function named create_daily_dir in backup.py. This function should take a string which will be a date in either year-month-day (2012-12-22) or month-day-year (12-22-2012) format. Use that to create a directory like 2012-12-22 (year-month-day) in the financial directory (which is in the current directory).

This means that by calling create_daily_dir("04-22-2017"), we'd have a directory structure like financial/2017-04-22/.

My code:

import os


def create_daily_dir(string):
    if int(string.split("-")[2]) > 31:
        new_str = string.split("-")[2] + '-' + string.split("-")[0] + '-' + string.split("-")[1]
    else:
        new_str = string
    os.makedirs(new_str, exist_ok=True)

I tried this out on my system and it creates the folder just like the prompt asks, am I missing something?

Is there a better way to parse datetime (datetime.strptime ?) that recognizes whether the string is YYYYMMDD or MMDDYYYY without an if statement?

3 Answers

Jeff Muday
MOD
Jeff Muday
Treehouse Moderator 28,722 Points
Jeff Muday
Jeff Muday
Treehouse Moderator 28,722 Points

You're incredibly clever! You will make a good programmer! The only thing you missed to pass the challenge was adding 'financial/' as the beginning part of the path, see below.

import os

def create_daily_dir(string):
    if int(string.split("-")[2]) > 31:
        new_str = string.split("-")[2] + '-' + string.split("-")[0] + '-' + string.split("-")[1]
    else:
        new_str = string
    os.makedirs('financial/' + new_str, exist_ok=True)

Another way this can be done is to import some additional functionality from the datetime library. My version will throw an error if a date comes in that does not conform to the format. Is that better? You can be the judge.

import os
import datetime

def create_daily_dir(string, path='financial'):
    # try to decode date string to a datetime
    try:
        this_date = datetime.datetime.strptime( string, "%Y-%m-%d" ) #format type YYYY-mm-dd
    except:
        this_date = datetime.datetime.strptime( string, "%m-%d-%Y" ) #format type mm-dd-YYYY
    # convert back to the proper format    
    date_str = datetime.datetime.strftime(this_date, '%Y-%m-%d')
    os.makedirs(os.path.join(path, date_str))
hamsternation
hamsternation
26,616 Points

nice! that's so weird! I could have swore i tried adding the path as well, must have made a typo.

I actually figured out how to solve it with 2 lines! I was out of ideas and found a really useful library, dateutil:

import os
import dateutil.parser

def create_daily_dir(string):
    os.makedirs(os.path.join('financial/',dateutil.parser.parse(string).strftime('%Y-%m-%d')), exist_ok=True)

Thanks!

Tom Nguyen
Tom Nguyen
33,501 Points
Tom Nguyen
Tom Nguyen
33,501 Points

What I did

import os

def create_daily_dir(string):
    date = string.split("-")
    if len(date) == 4: # the format coming in is mm-dd-yyyy
        directory_path = "financial/" + "{}-{}-{}".format(date[2],date[0],date[1])
        os.makedirs(directory_path, exist_ok=True)
    else: # the format of string is yyyy-dd-mm
        os.makedirs("financial/"+string, exist_ok=True)
Jeff Muday
MOD
Jeff Muday
Treehouse Moderator 28,722 Points
Jeff Muday
Jeff Muday
Treehouse Moderator 28,722 Points

Dateutil is very cool (and simpler)! Is it available in our Challenges environment?

hamsternation
hamsternation
26,616 Points

It imported successfully :) :D