spark-instrumented-optimizer/python/pyspark/util.py
Gabor Somogyi 3729efb4d0 [SPARK-26856][PYSPARK] Python support for from_avro and to_avro APIs
## What changes were proposed in this pull request?

Avro is built-in but external data source module since Spark 2.4 but  `from_avro` and `to_avro` APIs not yet supported in pyspark.

In this PR I've made them available from pyspark.

## How was this patch tested?

Please see the python API examples what I've added.

cd docs/
SKIP_SCALADOC=1 SKIP_RDOC=1 SKIP_SQLDOC=1 jekyll build
Manual webpage check.

Closes #23797 from gaborgsomogyi/SPARK-26856.

Authored-by: Gabor Somogyi <gabor.g.somogyi@gmail.com>
Signed-off-by: Hyukjin Kwon <gurwls223@apache.org>
2019-03-11 10:15:07 +09:00

141 lines
4.7 KiB
Python

# -*- coding: utf-8 -*-
#
# Licensed to the Apache Software Foundation (ASF) under one or more
# contributor license agreements. See the NOTICE file distributed with
# this work for additional information regarding copyright ownership.
# The ASF licenses this file to You under the Apache License, Version 2.0
# (the "License"); you may not use this file except in compliance with
# the License. You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#
import re
import sys
import inspect
from py4j.protocol import Py4JJavaError
__all__ = []
def _exception_message(excp):
"""Return the message from an exception as either a str or unicode object. Supports both
Python 2 and Python 3.
>>> msg = "Exception message"
>>> excp = Exception(msg)
>>> msg == _exception_message(excp)
True
>>> msg = u"unicöde"
>>> excp = Exception(msg)
>>> msg == _exception_message(excp)
True
"""
if isinstance(excp, Py4JJavaError):
# 'Py4JJavaError' doesn't contain the stack trace available on the Java side in 'message'
# attribute in Python 2. We should call 'str' function on this exception in general but
# 'Py4JJavaError' has an issue about addressing non-ascii strings. So, here we work
# around by the direct call, '__str__()'. Please see SPARK-23517.
return excp.__str__()
if hasattr(excp, "message"):
return excp.message
return str(excp)
def _get_argspec(f):
"""
Get argspec of a function. Supports both Python 2 and Python 3.
"""
if sys.version_info[0] < 3:
argspec = inspect.getargspec(f)
else:
# `getargspec` is deprecated since python3.0 (incompatible with function annotations).
# See SPARK-23569.
argspec = inspect.getfullargspec(f)
return argspec
class VersionUtils(object):
"""
Provides utility method to determine Spark versions with given input string.
"""
@staticmethod
def majorMinorVersion(sparkVersion):
"""
Given a Spark version string, return the (major version number, minor version number).
E.g., for 2.0.1-SNAPSHOT, return (2, 0).
>>> sparkVersion = "2.4.0"
>>> VersionUtils.majorMinorVersion(sparkVersion)
(2, 4)
>>> sparkVersion = "2.3.0-SNAPSHOT"
>>> VersionUtils.majorMinorVersion(sparkVersion)
(2, 3)
"""
m = re.search(r'^(\d+)\.(\d+)(\..*)?$', sparkVersion)
if m is not None:
return (int(m.group(1)), int(m.group(2)))
else:
raise ValueError("Spark tried to parse '%s' as a Spark" % sparkVersion +
" version string, but it could not find the major and minor" +
" version numbers.")
def fail_on_stopiteration(f):
"""
Wraps the input function to fail on 'StopIteration' by raising a 'RuntimeError'
prevents silent loss of data when 'f' is used in a for loop in Spark code
"""
def wrapper(*args, **kwargs):
try:
return f(*args, **kwargs)
except StopIteration as exc:
raise RuntimeError(
"Caught StopIteration thrown from user's code; failing the task",
exc
)
return wrapper
def _print_missing_jar(lib_name, pkg_name, jar_name, spark_version):
print("""
________________________________________________________________________________________________
Spark %(lib_name)s libraries not found in class path. Try one of the following.
1. Include the %(lib_name)s library and its dependencies with in the
spark-submit command as
$ bin/spark-submit --packages org.apache.spark:spark-%(pkg_name)s:%(spark_version)s ...
2. Download the JAR of the artifact from Maven Central http://search.maven.org/,
Group Id = org.apache.spark, Artifact Id = spark-%(jar_name)s, Version = %(spark_version)s.
Then, include the jar in the spark-submit command as
$ bin/spark-submit --jars <spark-%(jar_name)s.jar> ...
________________________________________________________________________________________________
""" % {
"lib_name": lib_name,
"pkg_name": pkg_name,
"jar_name": jar_name,
"spark_version": spark_version
})
if __name__ == "__main__":
import doctest
(failure_count, test_count) = doctest.testmod()
if failure_count:
sys.exit(-1)