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## What changes were proposed in this pull request? Currently column names of headers in CSV files are not checked against provided schema of CSV data. It could cause errors like showed in the [SPARK-23786](https://issues.apache.org/jira/browse/SPARK-23786) and https://github.com/apache/spark/pull/20894#issuecomment-375957777. I introduced new CSV option - `enforceSchema`. If it is enabled (by default `true`), Spark forcibly applies provided or inferred schema to CSV files. In that case, CSV headers are ignored and not checked against the schema. If `enforceSchema` is set to `false`, additional checks can be performed. For example, if column in CSV header and in the schema have different ordering, the following exception is thrown: ``` java.lang.IllegalArgumentException: CSV file header does not contain the expected fields Header: depth, temperature Schema: temperature, depth CSV file: marina.csv ``` ## How was this patch tested? The changes were tested by existing tests of CSVSuite and by 2 new tests. Author: Maxim Gekk <maxim.gekk@databricks.com> Author: Maxim Gekk <max.gekk@gmail.com> Closes #20894 from MaxGekk/check-column-names. |
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docs | ||
lib | ||
pyspark | ||
test_coverage | ||
test_support | ||
.coveragerc | ||
.gitignore | ||
MANIFEST.in | ||
pylintrc | ||
README.md | ||
run-tests | ||
run-tests-with-coverage | ||
run-tests.py | ||
setup.cfg | ||
setup.py |
Apache Spark
Spark is a fast and general cluster computing system for Big Data. It provides high-level APIs in Scala, Java, Python, and R, and an optimized engine that supports general computation graphs for data analysis. It also supports a rich set of higher-level tools including Spark SQL for SQL and DataFrames, MLlib for machine learning, GraphX for graph processing, and Spark Streaming for stream processing.
Online Documentation
You can find the latest Spark documentation, including a programming guide, on the project web page
Python Packaging
This README file only contains basic information related to pip installed PySpark. This packaging is currently experimental and may change in future versions (although we will do our best to keep compatibility). Using PySpark requires the Spark JARs, and if you are building this from source please see the builder instructions at "Building Spark".
The Python packaging for Spark is not intended to replace all of the other use cases. This Python packaged version of Spark is suitable for interacting with an existing cluster (be it Spark standalone, YARN, or Mesos) - but does not contain the tools required to set up your own standalone Spark cluster. You can download the full version of Spark from the Apache Spark downloads page.
NOTE: If you are using this with a Spark standalone cluster you must ensure that the version (including minor version) matches or you may experience odd errors.
Python Requirements
At its core PySpark depends on Py4J (currently version 0.10.7), but some additional sub-packages have their own extra requirements for some features (including numpy, pandas, and pyarrow).