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Dataframes for Go GoDoc cover.run Go Report Card

Dataframes are used for statistics and data manipulation. You can think of a dataframe as an excel spreadsheet. This package is designed to be light-weight and intuitive.

The package is production ready but the API is not stable yet. Once stability is reached, version 1.0.0 will be tagged. It is recommended your package manager locks to a commit id instead of the master branch directly.

Dataframes

Creating a Dataframe

s1 := dataframe.NewSeriesInt64("day", nil, 1, 2, 3, 4, 5, 6, 7, 8) s2 := dataframe.NewSeriesFloat64("sales", nil, 50.3, 23.4, 56.2, nil, nil, 84.2, 72, 89) df := dataframe.NewDataFrame(s1, s2) fmt.Print(df.Table()) OUTPUT: +-----+-------+---------+ | | DAY | SALES | +-----+-------+---------+ | 0: | 1 | 50.3 | | 1: | 2 | 23.4 | | 2: | 3 | 56.2 | | 3: | 4 | NaN | | 4: | 5 | NaN | | 5: | 6 | 84.2 | | 6: | 7 | 72 | | 7: | 8 | 89 | +-----+-------+---------+ | 8X2 | INT64 | FLOAT64 | +-----+-------+---------+

Insert and Remove Row

df.Append(9, 123.6) df.Append(map[string]interface{}{ "day": 10, "sales": nil, }) df.Remove(0) OUTPUT: +-----+-------+---------+ | | DAY | SALES | +-----+-------+---------+ | 0: | 2 | 23.4 | | 1: | 3 | 56.2 | | 2: | 4 | NaN | | 3: | 5 | NaN | | 4: | 6 | 84.2 | | 5: | 7 | 72 | | 6: | 8 | 89 | | 7: | 9 | 123.6 | | 8: | 10 | NaN | +-----+-------+---------+ | 9X2 | INT64 | FLOAT64 | +-----+-------+---------+

Update Row

df.UpdateRow(0, map[string]interface{}{ "day": 3, "sales": 45, })

Sorting

sks := []dataframe.SortKey{	{Key: "sales", SortDesc: true},	{Key: "day", SortDesc: true}, } df.Sort(sks) OUTPUT: +-----+-------+---------+ | | DAY | SALES | +-----+-------+---------+ | 0: | 9 | 123.6 | | 1: | 8 | 89 | | 2: | 6 | 84.2 | | 3: | 7 | 72 | | 4: | 3 | 56.2 | | 5: | 2 | 23.4 | | 6: | 10 | NaN | | 7: | 5 | NaN | | 8: | 4 | NaN | +-----+-------+---------+ | 9X2 | INT64 | FLOAT64 | +-----+-------+---------+

Iterating

You can change the step and starting row. It may be wise to lock the dataframe before iterating.

The returned values are a map containing the name of the series (string) and the order of the series (int).

iterator := df.Values(dataframe.ValuesOptions{0, 1, true}) // Don't apply read lock because we are write locking from outside. df.Lock() for { row, vals := iterator() if row == nil { break	} fmt.Println(*row, vals) } df.Unlock() OUTPUT: 0 map[day:1 0:1 sales:50.3 1:50.3] 1 map[sales:23.4 1:23.4 day:2 0:2] 2 map[day:3 0:3 sales:56.2 1:56.2] 3 map[1:<nil> day:4 0:4 sales:<nil>] 4 map[day:5 0:5 sales:<nil> 1:<nil>] 5 map[sales:84.2 1:84.2 day:6 0:6] 6 map[day:7 0:7 sales:72 1:72] 7 map[day:8 0:8 sales:89 1:89]

Importing Data

The imports sub-package has support to import from csv, jsonl and directly from a sql database.

CSV

csvStr := ` Country,Date,Age,Amount,Id "United States",2012-02-01,50,112.1,01234 "United States",2012-02-01,32,321.31,54320 "United Kingdom",2012-02-01,17,18.2,12345 "United States",2012-02-01,32,321.31,54320 "United Kingdom",2012-02-01,NA,18.2,12345 "United States",2012-02-01,32,321.31,54320 "United States",2012-02-01,32,321.31,54320 Spain,2012-02-01,66,555.42,00241 ` df, err := imports.LoadFromCSV(ctx, strings.NewReader(csvStr)) OUTPUT: +-----+----------------+------------+--------+--------+--------+ | | COUNTRY | DATE | AGE | AMOUNT | ID | +-----+----------------+------------+--------+--------+--------+ | 0: | United States | 2012-02-01 | 50 | 112.1 | 01234 | | 1: | United States | 2012-02-01 | 32 | 321.31 | 54320 | | 2: | United Kingdom | 2012-02-01 | 17 | 18.2 | 12345 | | 3: | United States | 2012-02-01 | 32 | 321.31 | 54320 | | 4: | United Kingdom | 2012-02-01 | NA | 18.2 | 12345 | | 5: | United States | 2012-02-01 | 32 | 321.31 | 54320 | | 6: | United States | 2012-02-01 | 32 | 321.31 | 54320 | | 7: | Spain | 2012-02-01 | 66 | 555.42 | 00241 | +-----+----------------+------------+--------+--------+--------+ | 8X5 | STRING | STRING | STRING | STRING | STRING | +-----+----------------+------------+--------+--------+--------+

Exporting Data

The exports sub-package has support for exporting to csv, jsonl and MS Excel.

Optimizations

  • If you know the number of rows in advance, you can set the capacity of the underlying slice of a series using SeriesInit{}. This will preallocate memory and provide speed improvements.

Generic Series

Out of the box, there is support for string, time.Time, float64 and int64. Automatic support exists for float32 and all types of integers. There is a convenience function provided for dealing with bool.

There may be times that you want to use your own custom data types. You can either implement your own Series type or use the Generic Series.

civil.Date

import ( "time" "cloud.google.com/go/civil" ) sg := dataframe.NewSeries("date", civil.Date{}, nil, civil.Date{2018, time.May, 01}, civil.Date{2018, time.May, 02}, civil.Date{2018, time.May, 03}) s2 := dataframe.NewSeriesFloat64("sales", nil, 50.3, 23.4, 56.2) df := dataframe.NewDataFrame(sg, s2) OUTPUT: +-----+------------+---------+ | | DATE | SALES | +-----+------------+---------+ | 0: | 2018-05-01 | 50.3 | | 1: | 2018-05-02 | 23.4 | | 2: | 2018-05-03 | 56.2 | +-----+------------+---------+ | 3X2 | CIVIL DATE | FLOAT64 | +-----+------------+---------+

Other useful packages

  • remember-go - Cache slow database queries
  • mysql-go - Properly cancel slow MySQL queries
  • react - Build front end applications using Go
  • igo - A Go transpiler with cool new syntax such as fordefer (defer for for-loops)

Legal Information

The license is a modified MIT license. Refer to LICENSE file for more details.

© 2018 PJ Engineering and Business Solutions Pty. Ltd.

Final Notes

Feel free to enhance features by issuing pull-requests.

Star the project to show your appreciation.

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DataFrames for Go: For statistics, machine-learning, and data manipulation/exploration

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