[DOC] improve python doc for rdd.histogram and dataframe.join

## What changes were proposed in this pull request?

doc change only

## How was this patch tested?

doc change only

Author: Mortada Mehyar <mortada.mehyar@gmail.com>

Closes #14253 from mortada/histogram_typos.

2 files changed, 14 insertions, 14 deletions

diff --git a/python/pyspark/rdd.py b/python/pyspark/rdd.py
index 6afe769662..0508235c1c 100644
--- a/python/pyspark/rdd.py
+++ b/python/pyspark/rdd.py
@@ -1027,20 +1027,20 @@ class RDD(object):
 
         If your histogram is evenly spaced (e.g. [0, 10, 20, 30]),
         this can be switched from an O(log n) inseration to O(1) per
-        element(where n = # buckets).
+        element (where n is the number of buckets).
 
-        Buckets must be sorted and not contain any duplicates, must be
+        Buckets must be sorted, not contain any duplicates, and have
         at least two elements.
 
-        If `buckets` is a number, it will generates buckets which are
+        If `buckets` is a number, it will generate buckets which are
         evenly spaced between the minimum and maximum of the RDD. For
-        example, if the min value is 0 and the max is 100, given buckets
-        as 2, the resulting buckets will be [0,50) [50,100]. buckets must
-        be at least 1 If the RDD contains infinity, NaN throws an exception
-        If the elements in RDD do not vary (max == min) always returns
-        a single bucket.
+        example, if the min value is 0 and the max is 100, given `buckets`
+        as 2, the resulting buckets will be [0,50) [50,100]. `buckets` must
+        be at least 1. An exception is raised if the RDD contains infinity.
+        If the elements in the RDD do not vary (max == min), a single bucket
+        will be used.
 
-        It will return a tuple of buckets and histogram.
+        The return value is a tuple of buckets and histogram.
 
         >>> rdd = sc.parallelize(range(51))
         >>> rdd.histogram(2)
diff --git a/python/pyspark/sql/dataframe.py b/python/pyspark/sql/dataframe.py
index adf549dd02..8ff9403d59 100644
--- a/python/pyspark/sql/dataframe.py
+++ b/python/pyspark/sql/dataframe.py
@@ -613,16 +613,16 @@ class DataFrame(object):
     def join(self, other, on=None, how=None):
         """Joins with another :class:`DataFrame`, using the given join expression.
 
-        The following performs a full outer join between ``df1`` and ``df2``.
-
         :param other: Right side of the join
-        :param on: a string for join column name, a list of column names,
-            , a join expression (Column) or a list of Columns.
-            If `on` is a string or a list of string indicating the name of the join column(s),
+        :param on: a string for the join column name, a list of column names,
+            a join expression (Column), or a list of Columns.
+            If `on` is a string or a list of strings indicating the name of the join column(s),
             the column(s) must exist on both sides, and this performs an equi-join.
         :param how: str, default 'inner'.
             One of `inner`, `outer`, `left_outer`, `right_outer`, `leftsemi`.
 
+        The following performs a full outer join between ``df1`` and ``df2``.
+
         >>> df.join(df2, df.name == df2.name, 'outer').select(df.name, df2.height).collect()
         [Row(name=None, height=80), Row(name=u'Bob', height=85), Row(name=u'Alice', height=None)]