An Introduction to DataFrames
Bogumił Kamiński, Dec 25, 2017
A brief introduction to basic usage of DataFrames. Tested under master from 2017-12-05 and Julia 0.6.2.
I will try to keep it up to date as the package evolves. This tutorial covers DataFrames, CSV, Missings, and CategoricalArrays, as they constitute the core of DataFrames.
In the last extras part mentions selected functionalities of selected useful packages that I find useful for data manipulation, currently those are: FreqTables, DataFramesMeta.
TOC
| File | Topic |
|---|---|
| 01_constructors.ipynb | Creating DataFrame and conversion |
| 02_basicinfo.ipynb | Getting summary information |
| 03_missingvalues.ipynb | Handling missing values |
| 04_loadsave.ipynb | Loading and saving DataFrames |
| 05_columns.ipynb | Working with columns of DataFrame |
| 06_rows.ipynb | Working with row of DataFrame |
| 07_factors.ipynb | Working with categorical data |
| 08_joins.ipynb | Joining DataFrames |
| 09_reshaping.ipynb | Reshaping DataFrames |
| 10_transforms.ipynb | Transforming DataFrames |
| 11_performance.ipynb | Performance tips |
| 12_pitfalls.ipynb | Possible pitfalls |
| 13_extras.ipynb | Additional interesting packages |
Changelog:
| Date | Changes |
|---|---|
| 2017-12-05 | Initial release |
| 2017-12-06 | Added description of insert!, merge!, empty!, categorical!, delete!, DataFrames.index |
| 2017-12-09 | Added performance tips |
| 2017-12-10 | Added pitfalls |
| 2017-12-18 | Added additional worthwhile packages: FreqTables and DataFramesMeta |
| 2017-12-29 | Added description of filter and filter! |
| 2017-12-31 | Added description of conversion to Matrix |
Core functions summary
- Constructors:
DataFrame - Getting summary:
size,nrow,ncol,length,describe,showcols,names,eltypes,head,tail - Handling missing:
missing(singleton instance ofMissing),ismissing,Missings.T,skipmissing,Missings.replace,allowmissing,disallowmissing,allowmissing!,completecases,dropmissing,dropmissing! - Loading and saving:
CSV(package),JLD(package),CSV.read,CSV.write,save(fromJLD),load(fromJLD) - Working with columns:
rename,rename!,names!,hcat,insert!,DataFrames.hcat!,merge!,delete!,empty!,categorical!,DataFrames.index - Working with rows:
sort!,sort,append!,vcat,push!,view,filter,filter!,deleterows!,unique,nonunique,unique! - Working with categorical:
categorical,cut,isordered,ordered!,levels,unique,levels!,droplevels!,get,recode,recode! - Joining:
join - Reshaping:
stack,melt,stackdf,meltdf,unstack - Transforming:
groupby,vcat,by,aggregate,eachcol,eachrow,colwise - Extras:
- FreqTables:
freqtable,prop - DataFramesMeta:
@with,@where,@select,@transform,@orderby,@linq,by,based_on
- FreqTables:
React
Typescript
Django
Laravel
Facebook
Microsoft
Google
Alibaba
D3
Tencent