In this example, we first define two input data providers DP1
and DP2
, each with 5 columns id
and value
. We also define a list of join keys join_keys
(in this case just “id”).
Next, we use a list comprehension to create a string join_clause
containing the join condition based on the join keys. We use the col
function from pyspark.sql.functions
to specify the column names.
Finally, we perform an inner join on DP1
and DP2
using join_clause
as the join condition, and store the result in result
. We then show the result using the show()
method.
Note that in a real-world scenario, you may need to modify this code to fit the specific requirements of your data and use case.
from pyspark.sql.functions import col
Sample input data
DP1 = spark.createDataFrame([(1, "A", 10, 100, "X"), (2, "B", 20, 200, "Y"), (3, "C", 30, 300, "Z")], ["id", "value", "col1", "col2", "col3"]) DP2 = spark.createDataFrame([(1, "X", 1000, 10000, "A"), (2, "Y", 2000, 20000, "B"), (3, "Z", 3000, 30000, "C")], ["id", "value", "col1", "col2", "col3"]) join_keys = ["id"]
Create join clause based on join keys
join_clause = " AND ".join([f"DP1.{key} = DP2.{key}" for key in join_keys])
Perform inner join on DP1 and DP2
result = DP1.join(DP2, col(join_clause), "inner")
Show result
result.show()
In this example, we use the zip
function to create a list of pairs of corresponding elements from the join_keys_1
and join_keys_2
lists.
Next, we use these pairs to create the join condition using a list comprehension. For each pair of keys, we create a string that compares the corresponding columns in DP1
and DP2
using the =
operator. We join these strings using the AND
operator to create the full join condition.
Finally, we perform an inner join on DP1
and DP2
using join_clause
as the join condition, and display the result.
Note that the zip
function requires that the two lists have the same length. If your lists have different lengths, you will need to adjust your code accordingly.
from pyspark.sql.functions import col
Sample input data
DP1 = spark.createDataFrame([(1, "A", 10), (2, "B", 20), (3, "C", 30)], ["id", "value", "col1"])
DP2 = spark.createDataFrame([(1, "X", 100), (2, "Y", 200), (3, "Z", 300)], ["id", "value", "col1"])
join_keys_1 = ["id", "value"]
join_keys_2 = ["id", "col1"]
Zip the join_keys
join_pairs = zip(join_keys_1, join_keys_2)
Create join clause
join_clause = " AND ".join([f"DP1.{pair[0]} = DP2.{pair[1]}" for pair in join_pairs])
Perform inner join on DP1 and DP2
result = DP1.join(DP2, col(join_clause), "inner")
Show result
result.show()