How Year, Month in "def get_customers(yearmonth)" works

Q&A
,
#1 
def get_customers(yearmonth):
    year = yearmonth//100
    month = yearmonth-year*100
    date = dt.datetime(year, month, 1)

I really need to understand the working of year and month variables in this function …

Refer this - https://app.dataquest.io/m/468/business-metrics/8/churn-rate

2 Likes
#2

Hi @4jvarun

Basically the function takes an input yearmonth, in this case that’s a column in churn. That column has values like this 201101

So what it does is:

  1. Takes yearmonth and makes a floor division by 100 so you get only the year. IE: 201101 // 100 = 2011
  2. Takes yearmonth and substract year (that you found in the step before) and multiplies it by 100 IE: 201101 - 2011 * 100 = 201101 - 201100 = 1
  3. Then you use dt.datetime(year, month, 1) to transform it into a date

Basically year and month are temporal variables that you create to “save” chunks of data that you might need later

So the function would be something like this:

def get_customers(201101):
  year = 201101 // 100
  year = 2011
  month = 201101 - 2011 * 100
  month = 1
  date = dt.datetime(year, month, 1)
  date = dt.datetime(2011, 1, 1)

Hope i made myself clear and that you understood the working of year and month

Good luck!

6 Likes
#3

Thanks, that was of great help

#4

Hi @4jvarun,

Was confusing for me too, but I went with very easy basic approach for this.

def get_customers(yearmonth):
    yearmonth = str(yearmonth) 
    year = int(yearmonth[:4])
    month = int(yearmonth[4:])
    first_date = dt.datetime(year,month,1)
    
    return ( (subs['start_date']<first_date)&(first_date <= subs['end_date']) ).sum()
2 Likes
#5

Hi! inside get_customers(), do i have to put yearmonth? or i can use anyword like xxxxxx to represent 201101?

#6

Hi!
No, when you are defining the function you can use whatever name you want, it’s like the helper in the for loop, just a temporal name that will be replaced when you call the function. So obviously the recomendation is that you use a word that helps to describe what you need as the argument. That’s why in this case yearmonth is used, but date would have been another option

#7

Excellent explanation.
Thank you