> For the complete documentation index, see [llms.txt](https://docs.invariant.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.invariant.io/data-science/apache-spark/pyspark-setup/dataframe-api.md).

# DataFrame API

This is a brief overview of the PySpark DataFrame API. 

#### Init Session

PySpark applications start with initializing `SparkSession`. When running in PySpark shell via pyspark executable, the shell automatically creates the session in the variable spark for users.

```
from pyspark.sql import SparkSession

spark = SparkSession.builder.getOrCreate()
```

#### Create DataFrame

 Create a DataFrame using `pyspark.sql.SparkSession.createDataFrame` , which takes the `schema` argument to specify the schema of the DataFrame. If not provided, it can infer the schema by sampling the data.

```
from datetime import datetime, date
import pandas as pd
from pyspark.sql import Row

df = spark.createDataFrame([
    Row(a=16, b=2., c='jane', d=date(2010, 1, 1), e=datetime(2021, 1, 1, 12, 0)),
    Row(a=16, b=3., c='john', d=date(2010, 2, 1), e=datetime(2021, 1, 2, 12, 0)),
    Row(a=32, b=5., c='alex', d=date(2010, 3, 1), e=datetime(2022, 1, 3, 12, 0))
])
df
```

The DataFrame results and schema can be displayed using the commands show below

```
# All DataFrames above result same.
df.show()
df.printSchema()
```

```
+---+---+-----+----------+-------------------+
|   a|  b|   c|         d|                  e|
+----+---+----+----------+-------------------+
|  16|2.0|jane|2000-01-01|2000-01-01 12:00:00|
|  32|3.0|john|2000-02-01|2000-01-02 12:00:00|
|  64|4.0|alex|2000-03-01|2000-01-03 12:00:00|
+----+---+----+----------+-------------------+

root
 |-- a: long (nullable = true)
 |-- b: double (nullable = true)
 |-- c: string (nullable = true)
 |-- d: date (nullable = true)
 |-- e: timestamp (nullable = true)

```

### Viewing Data

The rows of a DataFrame can be displayed using `DataFrame.show()`.

```
df.show(1)
```

```
+----+---+-------+----------+-------------------+
|   a|  b|      c|         d|                  e|
+----+---+-------+----------+-------------------+
|  16|2.0|jane|2000-01-01|2000-01-01 12:00:00|
+----+---+-------+----------+-------------------+
only showing top 1 row

```


---

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