https://www.databricks.com/notebooks/recitibikenycdraft/data-preparation.html

Could someone help to see in that Step 3: Prepare Calendar Info

# derive complete list of dates between first and last dates

dates = (

spark

.range(0,days_between).withColumnRenamed('id','days')

.withColumn('init_date', lit(first_date))

.selectExpr('cast(date_add(init_date, days) as timestamp) as date')

)

what does 'days' refer to in the last selectExpr sentence? it seems to be me not defined. is it meant to be 'days_between'? If i replace 'days' with 'days_between', it also breaks, because it expects a integer value, and not a variable.

Thanks.