Tag: structType

This post is how to create a DataFrame in pyspark.

First we need a spark Session. See PySpark: Create a Spark Session for my details on that.

Next we need to import

from pyspark.sql import Row
from pyspark.sql.types import StringType, DecimalType, TimestampType, FloatType, IntegerType, LongType, StructField, StructType

Then you create the schema

schema = StructType([
    StructField('id', IntegerType()),
    .....
])

data = [Row(id=1)]

Create the DataFrame

df = spark.createDataFrame(data, schema=schema)

If you want to use a JSON file to build your schema do the following

import json
from pyspark.sql.types import StructType

data = {
    "fields": [
        {
            "metadata": {},
            "name": "column_a",
            "nullable": false,
            "type": "string"
        }
    ],
    "type": "struct"
}

json_schema = json.loads(data)
table_schema = StructType.fromJson(dict(json_schema))

df = spark.createDataFrame(data, schema=table_schema)