DataFrame

Object –> DataFrame

A data structure to support indexing, binary operations, sorting, selecting, and other APIs.

dotnet add package Microsoft.Data.Analysis

Accessing

Elements

// Access the element at row, col:
df[row, col]
// or
df.Rows[row, col]

Rows

// Access the nth row:
df.Rows[n]

Columns

// Access a column by name:
df["column_name"]

// Access the nth column:
df.Columns[n]

DataFrame

// Filter the DataFrame:
df.Filter(df.Columns["column"].ElementwiseGreaterThan(50)) // All rows in column with values > 50.

Manipulating

Elements

df[row, col] = value;

Rows

// Add a row:
df.Append(new List<KeyValuePair<string, object>>() 
{
    new KeyValuePair<string, object>("foo_column", value),
    new KeyValuePair<string, object>("bar_column", value),
    new KeyValuePair<string, object>("baz_column", value)
}, true);

Columns

// Manipulate all rows of a column:
df.Columns["column_name"] = df.Columns["column_name"] + value;

// Add a column:
df.Columns.Add(new DataFrameColumn("column_name", numberOfRows);
// In place of `numberOfRows`, consider `df.Rows.Count()`

// Fill the nulls in a column with a value:
df.Columns["column_name"].FillNulls(value, true);

DataFrame

Sorting

// Sort (order) by ascending:
df.OrderBy("column");

// Sort (order) by descending:
df.OrderByDescending("column");

Grouping

// Group dataframe rows by unique value in columns:
var groupByData = df.GroupBy("column");

Merging

// Merge df2 into df1 using a column of Type named df1_column_name in df1 and df2_column_name in df2:
df1.Merge<Type>(df2, "df1_column_name", "df2_column_name");

// Merge df2 with df1 on the common column named "Date" of type DateTime:
df1.Merge<DateTime>(df2, "Date", "Date");

Properties

• Columns - Returns the columns in the DataFrame as a DataFrameColumnCollection.
• Item(rowIndex, colIndex) - An indexer to get or set values.
• Item(someString) - An indexer based on Name.
• Rows - Returns the rows in the DataFrame as a DataFrameRowCollection.

Methods

• AddPrefix
• AddSuffix
• Append
• Clamp
• Clone - Return a full copy of the DataFrame.
• Divide
• DropNulls(DropNullOptions) - Return a DataFrame with no missing values.
• FillNulls
• Filter
• GroupBy - Group the rows in the DataFrame by unique values.
• Head(n) - Return the first n rows of the DataFrame.
• Info() - Generate a concise summary of each column in the DataFrame.
• Join
• LoadCsv - Read a CSV into a DataFrame.
• Merge - Merge DataFrames with a database style join.
• Modulo
• OrderBy - Orders the DataFrame by a specified column.
• Tail(n) - Return the last n rows of the DataFrame.
• WriteCsv - Write a DataFrame to a CSV.

Comparison Methods

• ElementwiseEquals
• ElementwiseGreaterThan
• ElementwiseGreaterThanOrEqual
• ElementwiseLessThan
• ElementwiseLessThanOrEqual
• ElementwiseNotEquals

Mathematical Methods

• Add
• And
• Divide
• Modulo
• Multiply
• Or
• Subtract
• Xor
• ReverseAdd
• ReverseAnd
• ReverseDivide
• ReverseModulo
• ReverseMultiply
• ReverseSubtract
• ReverseXor

Statistical Methods

• Description() - Generate descriptive statcs that summarize each numeric column.
• Sample(n) - Return a random sample of n rows.