pysparkstr-to-date

Convert a date string with different formatting's and month abbreviation in Dutch using to_date in PySpark


I need to convert a date string to a DateType, but I've several challenges using to_date.

Formatting for day works well (1 or 2 digits), month is a Dutch abbreviation and doesn't work (works only if the abbreviation is equal to English), and year is 2 or 4 digits (missing centuries!).

What's the best way to convert these all to a DateType?
I couldn't find an option to set locale to NL using the formatting.

I created an UDF, but don't know if this is the best way to fix this.
The 19 for century is debatable.

Code:

@F.udf(T.StringType())
def convert_date(s):
    
    month_dict = {"jan":"01", "feb":"02", "mrt":"03", "apr":"04", "mei":"05", "jun":"06", "jul":"07", "aug":"08", "sep":"09", "okt":"10", "nov":"11", "dec":"12" }
    
    day, month, year = s.split("-")
    if len(day) == 1:
        day = '0' + day
    if len(year) < 4:
        year = '19' + year
        
    date = day + "-" + month_dict[month] + "-" + year
        
    return date
  
df = df.withColumn('DateOfBirth_new', F.to_date(convert_date(F.col("DateOfBirth"), "dd-M-yyyy"))

DateFrame:

df = spark.createDataFrame([
 ["2-feb-1966"],
 ["05-mei-1974"],
 ["3-mrt-83"],
 ["05-mrt-1983"],
 ["12-jun-75"]
]).toDF("DateOfBirth")

Solution

  • month_dict = {"jan":"01", "feb":"02", "mrt":"03", "apr":"04", "mei":"05", "jun":"06", "jul":"07", "aug":"08", "sep":"09", "okt":"10", "nov":"11", "dec":"12" }
    for key, item in month_dict.items():
        df= df.withColumn('column', regexp_replace('column', key, item))