from pyspark.sql.types import StringType
from pyspark.sql import functions as F
columns = ["ID", "A", "B", "C"]
data = [("1fe2", "2022-4-21", "2020-9-12", "2022-3-2"), ("3gef", "2021-5-22", "2019-3-4", "2022-4-2")]
df = spark.createDataFrame(data, columns)

// first concat the col name to the value

for col_name in (df.schema.fieldNames()):
    if col_name != "ID":
        df = df.withColumn(col_name, F.concat_ws(' ', F.col(col_name), F.lit(col_name)))

// then least() on each row

df.select(df.ID, F.least(df.A, df.B, df.C)).show()