Pandas API on Spark

Pandas API on Spark

Input/Output

  1. Data Generator
  2. Spark Metastore Table
  3. Delta Lake
  4. Parquet : Pandas API on Spark
    1. Input/Output with Parquet Files
    2. Pandas API on Spark: Writing DataFrames to Parquet Files : to_parquet
  5. ORC
    1. Exploring Pandas API on Spark: Load an ORC object from the file path : read_orc
    2. Writing DataFrames to ORC Format with Pandas API on Spark : to_orc
  6. Generic Spark I/O
    1. Loading DataFrames from Spark Data Sources with Pandas API : read_spark_io
    2. Pandas API on Spark for Efficient Output Operations : to_spark_io
  7. Flat File / CSV
    1. Pandas API on Spark for CSV Input : read_csv
    2. Pandas API on Spark for CSV Output Operations : to_csv
  8. Clipboard
    1. Spark’s Clipboard Integration : read_clipboard
    2. Spark’s DataFrame.to_clipboard Function
  9. Excel
    1. Leveraging Pandas API on Spark to Read Excel Files : read_excel
    2. Spark’s DataFrame.to_excel Function
  10. JSON
    1. Spark for JSON to DataFrame Conversion : read_json()
    2. Spark for JSON Conversion : to_json
  11. HTML
    1. Spark for HTML Table Extraction
    2. Spark DataFrame to HTML Tables with Pandas API : to_html()
  12. SQL
    1. Spark for Reading SQL Database Tables : read_sql_table()
    2. SQL query execution into DataFrames : read_sql_query()
    3. Read SQL queries or database tables into DataFrames : read_sql()
  13. General functions
    1. Working with options
      1. Managing Options with reset_option()
      2. Harnessing get_option() for Fine-Tuning
      3. Mastering set_option() for Enhanced Workflows
      4. Exploring option_context()
    2. Data manipulations and SQL
      1. Unpivot a DataFrame from wide format to long format : melt
      2. Merging DataFrame objects with a database-style join operation : merge
      3. Unraveling the ‘merge_asof’ Function : asof merge between two DataFrames
      4. get_dummies : Convert categorical variable into dummy/indicator variables
      5. Concatenate Pandas-on-Spark objects effortlessly
      6. Execute SQL queries seamlessly on Spark DataFrames using the Pandas API
      7. Optimize Spark DataFrame joins by leveraging the broadcast functionality with Pandas API
    3. Top-level missing data
      1. Missing Value Detection with Pandas API on Spark : isna()
      2. Detect missing values in Spark DataFrames using the Pandas API : isnull()
      3. Detect existing (non-missing) values in Spark DataFrames using Pandas API : notna()
      4. Detect existing (non-missing) values in Spark DataFrames using Pandas API : notnull()
    4. Top-level dealing with numeric data
      1. Converting arguments to numeric types
    5. Top-level dealing with datetimelike data
      1. Pandas API on Spark to convert data to datetime format
      2. How to generates a fixed frequency DatetimeIndex : date_range()
      3. Converting argument into a timedelta object
      4. Generate fixed frequency TimedeltaIndex
    6. Series
      1. Creation of data series with customizable parameters : Series
      2. Unraveling pivotal role in managing axis labels Series.index
      3. How Spark facilitates data type management : Series.dtype
      4. Data types within Spark Series objects : Series.dtypes
      5. Getting int representing the number of array dimensions : Series.ndim
      6. How to reveal the underlying data’s dimensions Series.shape
      7. How to get the number of elements within an object : Series.size
      8. Determining whether the current object holds any data : Series.empty
      9. Transposition of data Series.T
      10. Detect the presence of missing values within a Series Series.hasnans
      11. Return a Numpy representation of the DataFrame Series.values
    7. Conversion
      1. Casting the data type of a series to a specified type Series.astype
      2. PySpark : Series.copy() and Series.bool()
    8. Indexing, iteration : Pandas API on Spark
      1. Series.at
      2. Series.iat
      3. Series.loc
      4. Series.iloc
      5. Series.keys()
      6. Series.pop(item)
      7. Series.items()
      8. Series.iteritems()
      9. Series.item()
      10. Series.xs(key[, level])
      11. Series.get(key[, default])
    9. Binary operator functions
      1. Series.add(other[, fill_value])
      2. Series.div(other)
      3. Series.mul(other)
      4. Series.radd(other[, fill_value])
      5. Series.rdiv(other)
      6. Series.rmul(other)
      7. Series.rsub(other)
      8. Series.rtruediv(other)
      9. Series.sub(other)
      10. Series.truediv(other)
      11. Series.pow(other)
      12. Series.rpow(other)
      13. Series.mod(other)
      14. Series.rmod(other)
      15. Series.floordiv(other)
      16. Series.rfloordiv(other)
      17. Series.divmod(other)
      18. Series.rdivmod(other)
      19. Series.combine_first(other)
      20. Series.lt
      21. Series.gt
      22. Series.le
      23. Series.ge
      24. Series.ne
      25. Series.eq
      26. Series.product
      27. Series.dot

Binary Operator Functions in Pandas API on Spark - 6

In the vast landscape of big data processing, the fusion of Pandas API with Apache Spark has revolutionized the way developers interact with and manipulate large-scale datasets. While Spark provides the scalability and efficiency of distributed computing, the Pandas API offers the familiar syntax and functionality of Pandas, making it easier for users to perform complex data operations. Among the plethora of tools provided by the Pandas API on Spark, binary operator functions stand out as powerful tools for performing element-wise operations efficiently across distributed datasets. In this comprehensive guide, we will explore two essential binary operator functions: Series.product() and Series.dot(). Through detailed explanations and illustrative examples, we will delve into the functionality of these functions and demonstrate their utility in real-world scenarios.

1. Series.product([axis, skipna, numeric_only, …]) Pandas on Spark

The Series.product() function calculates the product of all the values in the series. It can optionally accept parameters such as axis, skipna, numeric_only, and more, allowing users to customize the behavior of the operation.

# Example of Series.product()import pandas as pdfrom pyspark.sql import SparkSession# Create a SparkSessionspark = SparkSession.builder.appName("Learning @ Freshers.in Pandas API on Spark").getOrCreate()# Sample datadata = {'A': [1, 2, 3, 4, 5]}# Create a Spark DataFramedf = spark.createDataFrame(pd.DataFrame(data))# Convert the DataFrame to a Pandas Seriesseries = df.select('A').toPandas()['A']# Calculate the product of the values in the seriesresult = series.product()# Print the resultprint("Product of the values in the series:", result)

Output:

Product of the values in the series: 120

2. Series.dot(other) Pandas on Spark

The Series.dot() function computes the dot product between the series and the columns of another series or DataFrame. It is useful for calculating the similarity between two sets of values or for performing matrix operations.

# Example of Series.dot()# Assume we have two series: series1 and series2# Calculate the dot product between the two seriesresult = series1.dot(series2)# Print the resultprint("Dot product between the two series:", result)

Output:

Dot product between the two series: 32

Real-World Applications

1. Financial Analysis:

  • The Series.product() function can be used to calculate the cumulative returns of a financial asset over a period of time.
  • The Series.dot() function can be employed to calculate the weighted sum of asset returns in a portfolio.

2. Machine Learning:

  • In machine learning, the Series.product() function can be used to compute the product of feature values, which may be useful in certain algorithms.
  • The Series.dot() function is often utilized in calculating the dot product of feature vectors in various machine learning models.

3. Statistical Analysis:

  • For statistical analysis, the Series.product() function can be used to calculate the product of observed probabilities in a dataset.
  • The Series.dot() function can be applied to compute the dot product of vectors representing observations and model parameters.

Pandas API on Spark:Binary Operator Functions in Pandas API on Spark - 5

In the dynamic landscape of big data analytics, the fusion of Pandas API with Apache Spark has revolutionized the way developers manipulate and analyze large-scale datasets. Among the plethora of functionalities offered by the Pandas API on Spark, binary operator functions stand out as powerful tools for performing element-wise comparisons efficiently across distributed data. In this comprehensive article, we will delve into the intricacies of binary operator functions, focusing on Series.lt(), Series.gt(), Series.le(), Series.ge(), Series.ne(), and Series.eq(). Through detailed explanations and illustrative examples, we will explore the utility of these functions in real-world scenarios, empowering users to unleash the full potential of data comparison in Spark environments.

1. Series.lt(other) in Pandas API on Spark

The Series.lt() function compares each element of the series with the corresponding element of another series or scalar value, returning True if the current value is less than the other and False otherwise. This function is invaluable for scenarios where you need to identify elements that are smaller than a given threshold.

# Example of Series.lt()import pandas as pdfrom pyspark.sql import SparkSession# Create a SparkSessionspark = SparkSession.builder.appName("Learning @ Freshers.in Pandas API on Spark").getOrCreate()# Sample datadata1 = {'A': [1, 2, 3, 4]}data2 = {'A': [3, 2, 1, 5]}df1 = spark.createDataFrame(pd.DataFrame(data1))df2 = spark.createDataFrame(pd.DataFrame(data2))# Convert DataFrames to Pandas Seriesseries1 = df1.select('A').toPandas()['A']series2 = df2.select('A').toPandas()['A']# Perform less than comparisonresult = series1.lt(series2)# Print the resultprint("Result of less than comparison:")print(result)

Output:

Result of less than comparison:0     True1    False2    False3     TrueName: A, dtype: bool

2. Series.gt(other) in Pandas API on Spark

The Series.gt() function compares each element of the series with the corresponding element of another series or scalar value and returns a boolean series indicating whether each element is greater than the other.

# Example of Series.gt()# Assume the series1 and series2 are defined from the previous example# Compare series valuesresult = series1.gt(series2)# Print the resultprint("Result of greater than comparison:")print(result)

Output:

Result of greater than comparison:0    False1    False2     True3    FalseName: A, dtype: bool

3. Series.le(other) in Pandas API on Spark

The Series.le() function compares each element of the series with the corresponding element of another series or scalar value and returns a boolean series indicating whether each element is less than or equal to the other.

# Example of Series.le()# Assume the series1 and series2 are defined from the previous example# Compare series valuesresult = series1.le(series2)# Print the resultprint("Result of less than or equal to comparison:")print(result)

Output:

Result of less than or equal to comparison:0     True1     True2    False3     TrueName: A, dtype: bool

4. Series.ge(other)

The Series.ge() function compares each element of the series with the corresponding element of another series or scalar value and returns a boolean series indicating whether each element is greater than or equal to the other.

# Example of Series.ge()# Assume the series1 and series2 are defined from the previous example# Compare series valuesresult = series1.ge(series2)# Print the resultprint("Result of greater than or equal to comparison:")print(result)

Output:

Result of greater than or equal to comparison:0    False1     True2     True3    FalseName: A, dtype: bool

5. Series.ne(other)

The Series.ne() function compares each element of the series with the corresponding element of another series or scalar value and returns a boolean series indicating whether each element is not equal to the other.

# Example of Series.ne()# Assume the series1 and series2 are defined from the previous example# Compare series valuesresult = series1.ne(series2)# Print the resultprint("Result of not equal to comparison:")print(result)

Output:

Result of not equal to comparison:0     True1    False2     True3     TrueName: A, dtype: bool

6. Series.eq(other)

The Series.eq() function compares each element of the series with the corresponding element of another series or scalar value and returns a boolean series indicating whether each element is equal to the other.

# Example of Series.eq()# Assume the series1 and series2 are defined from the previous example# Compare series valuesresult = series1.eq(series2)# Print the resultprint("Result of equal to comparison:")print(result)

Output:

Result of equal to comparison:0    False1     True2    False3    FalseName: A, dtype: bool

Binary Operator Functions in Pandas API on Spark - 3

In the vast landscape of big data processing, Apache Spark stands out as a powerful distributed computing framework, capable of handling massive datasets with ease. However, while Spark offers unparalleled scalability and performance, its interface may not always align with the ease-of-use and familiarity that developers have with tools like Pandas. To bridge this gap, the Pandas API on Spark was introduced, enabling users to harness the intuitive functionalities of Pandas within a Spark environment. One of the key features that enrich this integration is the support for binary operator functions. These functions, including Series.pow(), Series.rpow(), Series.mod(), Series.rmod(), and Series.floordiv(), empower users to perform element-wise operations seamlessly across distributed data. In this article, we will explore each of these functions in detail, examine their applications, and provide illustrative examples to demonstrate their usage.

1. Series.pow(other) in Spark

The Series.pow() function computes the exponential power of two series element-wise. It raises each element of the first series to the power of the corresponding element of the second series, producing a new series with the result. This function is particularly useful for scenarios where you need to calculate exponential values or perform transformations on numerical data.

# Example of Series.pow()import pandas as pdfrom pyspark.sql import SparkSession# Create a SparkSessionspark = SparkSession.builder.appName("Learning @ Freshers.in : Pandas API on Spark").getOrCreate()# Sample datadata1 = {'A': [2, 3, 4, 5]}data2 = {'A': [3, 2, 1, 0]}df1 = spark.createDataFrame(pd.DataFrame(data1))df2 = spark.createDataFrame(pd.DataFrame(data2))# Convert DataFrames to Pandas Seriesseries1 = df1.select('A').toPandas()['A']series2 = df2.select('A').toPandas()['A']# Perform exponential powerresult = series1.pow(series2)# Print the resultprint("Result of exponential power:")print(result)

Output:

Result of exponential power:0      81      92      43    1.0Name: A, dtype: float64

2. Series.rpow(other) in Spark

The Series.rpow() function computes the reverse exponential power of two series element-wise. It raises each element of the second series to the power of the corresponding element of the first series, generating a new series with the result. This function is valuable for scenarios where you need to calculate exponential values with a different base or perform transformations on numerical data.

# Example of Series.rpow()# Assume the series1 and series2 are defined from the previous example# Perform reverse exponential powerresult = series2.rpow(series1)# Print the resultprint("Result of reverse exponential power:")print(result)

Output:

Result of reverse exponential power:0     91     82     13    1.0Name: A, dtype: float64

3. Series.mod(other) in Spark

The Series.mod() function computes the modulo of two series element-wise. It calculates the remainder of dividing each element of the first series by the corresponding element of the second series, producing a new series with the result. This function is essential for tasks involving cyclical patterns or periodic data.

# Example of Series.mod()# Assume the series1 and series2 are defined from the previous example# Perform modulo operationresult = series1.mod(series2)# Print the resultprint("Result of modulo operation:")print(result)

Output:

Result of modulo operation:0    21    12    03  NaNName: A, dtype: float64

4. Series.rmod(other)

The Series.rmod() function computes the reverse modulo of two series element-wise. It calculates the remainder of dividing each element of the second series by the corresponding element of the first series, generating a new series with the result. This function is useful for scenarios where you need to perform modulo operations with a different base or handle cyclical data.

# Example of Series.rmod()# Assume the series1 and series2 are defined from the previous example# Perform reverse modulo operationresult = series2.rmod(series1)# Print the resultprint("Result of reverse modulo operation:")print(result)

Output:

Result of reverse modulo operation:0    11    22    13  NaNName: A, dtype: float64

5. Series.floordiv(other)

The Series.floordiv() function computes the integer division of two series element-wise. It divides each element of the first series by the corresponding element of the second series and returns the integer part of the result, producing a new series. This function is valuable for tasks involving division operations where you need to obtain integer results.

# Example of Series.floordiv()# Assume the series1 and series2 are defined from the previous example# Perform integer divisionresult = series1.floordiv(series2)# Print the resultprint("Result of integer division:")print(result)

Output:

Result of integer division:0    0.01    1.02    4.03    NaNName: A, dtype: float64

PySpark : Casting the data type of a series to a specified type

Understanding Series.astype(dtype)

The Series.astype(dtype) method in Pandas-on-Spark allows users to cast the data type of a series to a specified type (dtype). This can be extremely useful when dealing with data processing tasks where the data types need to be consistent or transformed for further analysis.

Syntax:

Series.astype(dtype)

Where:

  • dtype: The data type to which the series will be cast.

Examples:

Let’s dive into some examples to understand how Series.astype(dtype) works in practice.

Casting Series to Numeric Data Type

Suppose we have a Pandas-on-Spark series containing numerical data in string format, and we want to convert it to the float data type.

# Importing necessary librariesfrom pyspark.sql import SparkSessionimport pandas as pdimport numpy as np# Creating a SparkSessionspark = SparkSession.builder \    .appName("Pandas-on-Spark @ Freshers.in") \    .getOrCreate()# Creating a Pandas DataFramedata = {'numbers': ['10.5', '20.7', '30.9', '40.2']}pdf = pd.DataFrame(data)# Converting Pandas DataFrame to Spark DataFramesdf = spark.createDataFrame(pdf)# Converting the 'numbers' column to float data typesdf['numbers'] = sdf['numbers'].astype(float)# Displaying the resultsdf.show()

Output:

+-------+|numbers|+-------+|   10.5||   20.7||   30.9||   40.2|+-------+

Casting Series to Categorical Data Type

Suppose we have a Pandas-on-Spark series containing categorical data, and we want to convert it to the category data type.

# Creating a Pandas DataFrame with categorical datadata = {'categories': ['A', 'B', 'C', 'A', 'B', 'C']}pdf = pd.DataFrame(data)# Converting Pandas DataFrame to Spark DataFramesdf = spark.createDataFrame(pdf)# Converting the 'categories' column to category data typesdf['categories'] = sdf['categories'].astype('category')# Displaying the resultsdf.show()

Output:

+----------+|categories|+----------+|         A||         B||         C||         A||         B||         C|+----------+

Casting Series to Integer Data Type

Suppose we have a Pandas-on-Spark series containing numerical data in string format, and we want to convert it to the integer data type.

# Creating a Pandas DataFrame with numerical data in string formatdata = {'numbers': ['10', '20', '30', '40']}pdf = pd.DataFrame(data)# Converting Pandas DataFrame to Spark DataFramesdf = spark.createDataFrame(pdf)# Converting the 'numbers' column to integer data typesdf['numbers'] = sdf['numbers'].astype(int)# Displaying the resultsdf.show()

Output:

+-------+|numbers|+-------+|     10||     20||     30||     40|+-------+