因为需要string数组，所以需要填充null并将字符串串串接起来：

df.fillna(
    'null'
).withColumn(
    'combine',
    func.array([func.concat_ws(': ', col, val) for col, val in [(func.lit(col), func.col(col)) for col in df.columns]])
).show(1, False)
+---+---+---+---+----+-------------------------------------+
|A  |B  |C  |D  |E   |combine                              |
+---+---+---+---+----+-------------------------------------+
|aa |bb |cc |dd |null|[A: aa, B: bb, C: cc, D: dd, E: null]|
+---+---+---+---+----+-------------------------------------+