Adding constant value column to spark dataframe

muon@ provided the correct answer above. Just adding a quick reproducible version to increase clarity.

>>> from pyspark.sql.functions import lit
>>> df = spark.createDataFrame([(1, 4, 3)], ['a', 'b', 'c'])
>>> df.show()
+---+---+---+
|  a|  b|  c|
+---+---+---+
|  1|  4|  3|
+---+---+---+

>>> df = df.withColumn("d", lit(5))
>>> df.show()
+---+---+---+---+
|  a|  b|  c|  d|
+---+---+---+---+
|  1|  4|  3|  5|
+---+---+---+---+

you need to import lit

either

from pyspark.sql.functions import *

will make lit available

or something like

import pyspark.sql.functions as sf
wamp = wamp.withColumn('region', sf.lit('NE'))