add character at character count in pyspark

Question

I'm looking for a way to insert special character at a specific character count in a string in pyspark :

"M202876QC0581AADMM01"
to
"M-202876-QC0581-AA-DMM01"

(1-6-6-2-)
insertion after 1char then after 6char then after 6char then after 2char

Tried something like below but no luck yet :

df = spark.createDataFrame([('M202876QC0581AADMM01',)], ['str'])
(df.withColumn("str", F.regexp_replace(F.col("str") ,  r"(\d{0})(\d{3})(\d{3})" , "$1-$2-$3"))).collect()

Out[121]: [Row(str='M-202-876QC0581AADMM01')]

Answer 1

You're close, try this :

from pyspark.sql.functions import regexp_replace

df = spark.createDataFrame([("M202876QC0581AADMM01",)], ["str"])

pat = r"^(.{1})(.{6})(.{6})(.{2})(.+)"
df = df.withColumn("str", regexp_replace("str", pat, r"$1-$2-$3-$4-$5"))

Output :

df.show(truncate=False)

+------------------------+
|str                     |
+------------------------+
|M-202876-QC0581-AA-DMM01|
+------------------------+