diff --git a/python/pyspark/sql/functions.py b/python/pyspark/sql/functions.py
index f892331d25186..24ea47b07a73b 100644
--- a/python/pyspark/sql/functions.py
+++ b/python/pyspark/sql/functions.py
@@ -38,11 +38,9 @@
     'bin',
     'coalesce',
     'countDistinct',
-    'e',
     'explode',
     'md5',
     'monotonicallyIncreasingId',
-    'pi',
     'rand',
     'randn',
     'sha1',
@@ -302,22 +300,6 @@ def countDistinct(col, *cols):
     return Column(jc)
 
 
-@since(1.5)
-def e():
-    """
-    Returns the float value that is closer than any other to e, the base of the natural
-    logarithms.
-
-    >>> e = sqlContext.createDataFrame([(1,)], ['a']).select((e()).alias('e')).collect()
-
-    >>> round(e[0][0], 10)
-    2.7182818285
-    """
-    sc = SparkContext._active_spark_context
-    jc = sc._jvm.functions.e()
-    return Column(jc)
-
-
 @since(1.4)
 def explode(col):
     """Returns a new row for each element in the given array or map.
@@ -373,22 +355,6 @@ def monotonicallyIncreasingId():
     return Column(sc._jvm.functions.monotonicallyIncreasingId())
 
 
-@since(1.5)
-def pi():
-    """
-    Returns the float value that is closer than any other to pi, the ratio of the circumference
-    of a circle to its diameter.
-
-    >>> pi = sqlContext.createDataFrame([(1,)], ['a']).select((pi()).alias('pi')).collect()
-
-    >>> round(pi[0][0], 10)
-    3.1415926536
-    """
-    sc = SparkContext._active_spark_context
-    jc = sc._jvm.functions.pi()
-    return Column(jc)
-
-
 @since(1.4)
 def rand(seed=None):
     """Generates a random column with i.i.d. samples from U[0.0, 1.0].
@@ -462,11 +428,11 @@ def sparkPartitionId():
 def strlen(col):
     """Calculates the length of a string expression.
 
-    >>> sqlContext.createDataFrame([('ABC',)], ['a']).select(strlen('a').alias('e')).collect()
-    [Row(e=3)]
+    >>> sqlContext.createDataFrame([('ABC',)], ['a']).select(strlen('a').alias('length')).collect()
+    [Row(length=3)]
     """
     sc = SparkContext._active_spark_context
-    return Column(sc._jvm.functions.strlen(col))
+    return Column(sc._jvm.functions.strlen(_to_java_column(col)))
 
 
 @ignore_unicode_prefix
diff --git a/sql/core/src/main/scala/org/apache/spark/sql/functions.scala b/sql/core/src/main/scala/org/apache/spark/sql/functions.scala
index 4d9a019058228..6a373cb5db07a 100644
--- a/sql/core/src/main/scala/org/apache/spark/sql/functions.scala
+++ b/sql/core/src/main/scala/org/apache/spark/sql/functions.scala
@@ -989,15 +989,6 @@ object functions {
    */
   def cosh(columnName: String): Column = cosh(Column(columnName))
 
-  /**
-   * Returns the double value that is closer than any other to e, the base of the natural
-   * logarithms.
-   *
-   * @group math_funcs
-   * @since 1.5.0
-   */
-  def e(): Column = EulerNumber()
-
   /**
    * Computes the exponential of the given value.
    *
@@ -1191,15 +1182,6 @@ object functions {
    */
   def log1p(columnName: String): Column = log1p(Column(columnName))
 
-  /**
-   * Returns the double value that is closer than any other to pi, the ratio of the circumference
-   * of a circle to its diameter.
-   *
-   * @group math_funcs
-   * @since 1.5.0
-   */
-  def pi(): Column = Pi()
-
   /**
    * Computes the logarithm of the given column in base 2.
    *