diff options
Diffstat (limited to 'python/pyspark/sql/dataframe.py')
| -rw-r--r-- | python/pyspark/sql/dataframe.py | 56 |
1 files changed, 28 insertions, 28 deletions
diff --git a/python/pyspark/sql/dataframe.py b/python/pyspark/sql/dataframe.py index 6f746d136b..6d42410020 100644 --- a/python/pyspark/sql/dataframe.py +++ b/python/pyspark/sql/dataframe.py @@ -96,7 +96,7 @@ class DataFrame(object): return self._lazy_rdd def toJSON(self, use_unicode=False): - """Convert a DataFrame into a MappedRDD of JSON documents; one document per row. + """Convert a :class:`DataFrame` into a MappedRDD of JSON documents; one document per row. >>> df.toJSON().first() '{"age":2,"name":"Alice"}' @@ -108,7 +108,7 @@ class DataFrame(object): """Save the contents as a Parquet file, preserving the schema. Files that are written out using this method can be read back in as - a DataFrame using the L{SQLContext.parquetFile} method. + a :class:`DataFrame` using the L{SQLContext.parquetFile} method. >>> import tempfile, shutil >>> parquetFile = tempfile.mkdtemp() @@ -139,7 +139,7 @@ class DataFrame(object): self.registerTempTable(name) def insertInto(self, tableName, overwrite=False): - """Inserts the contents of this DataFrame into the specified table. + """Inserts the contents of this :class:`DataFrame` into the specified table. Optionally overwriting any existing data. """ @@ -165,7 +165,7 @@ class DataFrame(object): return jmode def saveAsTable(self, tableName, source=None, mode="append", **options): - """Saves the contents of the DataFrame to a data source as a table. + """Saves the contents of the :class:`DataFrame` to a data source as a table. The data source is specified by the `source` and a set of `options`. If `source` is not specified, the default data source configured by @@ -174,12 +174,13 @@ class DataFrame(object): Additionally, mode is used to specify the behavior of the saveAsTable operation when table already exists in the data source. There are four modes: - * append: Contents of this DataFrame are expected to be appended to existing table. - * overwrite: Data in the existing table is expected to be overwritten by the contents of \ - this DataFrame. + * append: Contents of this :class:`DataFrame` are expected to be appended \ + to existing table. + * overwrite: Data in the existing table is expected to be overwritten by \ + the contents of this DataFrame. * error: An exception is expected to be thrown. - * ignore: The save operation is expected to not save the contents of the DataFrame and \ - to not change the existing table. + * ignore: The save operation is expected to not save the contents of the \ + :class:`DataFrame` and to not change the existing table. """ if source is None: source = self.sql_ctx.getConf("spark.sql.sources.default", @@ -190,7 +191,7 @@ class DataFrame(object): self._jdf.saveAsTable(tableName, source, jmode, joptions) def save(self, path=None, source=None, mode="append", **options): - """Saves the contents of the DataFrame to a data source. + """Saves the contents of the :class:`DataFrame` to a data source. The data source is specified by the `source` and a set of `options`. If `source` is not specified, the default data source configured by @@ -199,11 +200,11 @@ class DataFrame(object): Additionally, mode is used to specify the behavior of the save operation when data already exists in the data source. There are four modes: - * append: Contents of this DataFrame are expected to be appended to existing data. + * append: Contents of this :class:`DataFrame` are expected to be appended to existing data. * overwrite: Existing data is expected to be overwritten by the contents of this DataFrame. * error: An exception is expected to be thrown. - * ignore: The save operation is expected to not save the contents of the DataFrame and \ - to not change the existing data. + * ignore: The save operation is expected to not save the contents of \ + the :class:`DataFrame` and to not change the existing data. """ if path is not None: options["path"] = path @@ -217,7 +218,7 @@ class DataFrame(object): @property def schema(self): - """Returns the schema of this DataFrame (represented by + """Returns the schema of this :class:`DataFrame` (represented by a L{StructType}). >>> df.schema @@ -275,12 +276,12 @@ class DataFrame(object): """ Print the first 20 rows. + >>> df + DataFrame[age: int, name: string] >>> df.show() age name 2 Alice 5 Bob - >>> df - DataFrame[age: int, name: string] """ print self._jdf.showString().encode('utf8', 'ignore') @@ -481,8 +482,8 @@ class DataFrame(object): def join(self, other, joinExprs=None, joinType=None): """ - Join with another DataFrame, using the given join expression. - The following performs a full outer join between `df1` and `df2`:: + Join 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 joinExprs: Join expression @@ -582,8 +583,6 @@ class DataFrame(object): def select(self, *cols): """ Selecting a set of expressions. - >>> df.select().collect() - [Row(age=2, name=u'Alice'), Row(age=5, name=u'Bob')] >>> df.select('*').collect() [Row(age=2, name=u'Alice'), Row(age=5, name=u'Bob')] >>> df.select('name', 'age').collect() @@ -591,8 +590,6 @@ class DataFrame(object): >>> df.select(df.name, (df.age + 10).alias('age')).collect() [Row(name=u'Alice', age=12), Row(name=u'Bob', age=15)] """ - if not cols: - cols = ["*"] jcols = ListConverter().convert([_to_java_column(c) for c in cols], self._sc._gateway._gateway_client) jdf = self._jdf.select(self.sql_ctx._sc._jvm.PythonUtils.toSeq(jcols)) @@ -612,7 +609,7 @@ class DataFrame(object): def filter(self, condition): """ Filtering rows using the given condition, which could be - Column expression or string of SQL expression. + :class:`Column` expression or string of SQL expression. where() is an alias for filter(). @@ -666,7 +663,7 @@ class DataFrame(object): return self.groupBy().agg(*exprs) def unionAll(self, other): - """ Return a new DataFrame containing union of rows in this + """ Return a new :class:`DataFrame` containing union of rows in this frame and another frame. This is equivalent to `UNION ALL` in SQL. @@ -919,9 +916,10 @@ class Column(object): """ A column in a DataFrame. - `Column` instances can be created by:: + :class:`Column` instances can be created by:: # 1. Select a column out of a DataFrame + df.colName df["colName"] @@ -975,7 +973,7 @@ class Column(object): def substr(self, startPos, length): """ - Return a Column which is a substring of the column + Return a :class:`Column` which is a substring of the column :param startPos: start position (int or Column) :param length: length of the substring (int or Column) @@ -996,8 +994,10 @@ class Column(object): __getslice__ = substr # order - asc = _unary_op("asc") - desc = _unary_op("desc") + asc = _unary_op("asc", "Returns a sort expression based on the" + " ascending order of the given column name.") + desc = _unary_op("desc", "Returns a sort expression based on the" + " descending order of the given column name.") isNull = _unary_op("isNull", "True if the current expression is null.") isNotNull = _unary_op("isNotNull", "True if the current expression is not null.") |