[SPARK-8266] [SQL] add function translate

![translate](http://www.w3resource.com/PostgreSQL/postgresql-translate-function.png)

Author: zhichao.li <zhichao.li@intel.com>

Closes #7709 from zhichao-li/translate and squashes the following commits:

9418088 [zhichao.li] refine checking condition
f2ab77a [zhichao.li] clone string
9d88f2d [zhichao.li] fix indent
6aa2962 [zhichao.li] style
e575ead [zhichao.li] add python api
9d4bab0 [zhichao.li] add special case for fodable and refactor unittest
eda7ad6 [zhichao.li] update to use TernaryExpression
cdfd4be [zhichao.li] add function translate

1 files changed, 16 insertions, 0 deletions

diff --git a/python/pyspark/sql/functions.py b/python/pyspark/sql/functions.py
index 9f0d71d796..b5c6a01f18 100644
--- a/python/pyspark/sql/functions.py
+++ b/python/pyspark/sql/functions.py
@@ -1290,6 +1290,22 @@ def length(col):
     return Column(sc._jvm.functions.length(_to_java_column(col)))
 
 
+@ignore_unicode_prefix
+@since(1.5)
+def translate(srcCol, matching, replace):
+    """A function translate any character in the `srcCol` by a character in `matching`.
+    The characters in `replace` is corresponding to the characters in `matching`.
+    The translate will happen when any character in the string matching with the character
+    in the `matching`.
+
+    >>> sqlContext.createDataFrame([('translate',)], ['a']).select(translate('a', "rnlt", "123")\
+    .alias('r')).collect()
+    [Row(r=u'1a2s3ae')]
+    """
+    sc = SparkContext._active_spark_context
+    return Column(sc._jvm.functions.translate(_to_java_column(srcCol), matching, replace))
+
+
 # ---------------------- Collection functions ------------------------------
 
 @since(1.4)