# datar
A Grammar of Data Manipulation in python
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[Documentation][5] | [Reference Maps][15] | [Notebook Examples][16] | [API][17]
`datar` is a re-imagining of APIs for data manipulation in python with multiple backends supported. Those APIs are aligned with tidyrverse packages in R as much as possible.
## Installation
```shell
pip install -U datar
# install with a backend
pip install -U datar[pandas]
# More backends support will be added in the future
```
<!-- ## Maximum compatibility with R packages
|Package|Version|
|-|-|
|[dplyr][21]|1.0.8| -->
## Backends
|Repo|Badges|
|-|-|
|[datar-numpy][1]|![3] ![18]|
|[datar-pandas][2]|![4] ![19]|
## Example usage
```python
# with pandas backend
from datar import f
from datar.dplyr import mutate, filter, if_else
from datar.tibble import tibble
# or
# from datar.all import f, mutate, filter, if_else, tibble
df = tibble(
x=range(4), # or c[:4] (from datar.base import c)
y=['zero', 'one', 'two', 'three']
)
df >> mutate(z=f.x)
"""# output
x y z
<int64> <object> <int64>
0 0 zero 0
1 1 one 1
2 2 two 2
3 3 three 3
"""
df >> mutate(z=if_else(f.x>1, 1, 0))
"""# output:
x y z
<int64> <object> <int64>
0 0 zero 0
1 1 one 0
2 2 two 1
3 3 three 1
"""
df >> filter(f.x>1)
"""# output:
x y
<int64> <object>
0 2 two
1 3 three
"""
df >> mutate(z=if_else(f.x>1, 1, 0)) >> filter(f.z==1)
"""# output:
x y z
<int64> <object> <int64>
0 2 two 1
1 3 three 1
"""
```
```python
# works with plotnine
# example grabbed from https://github.com/has2k1/plydata
import numpy
from datar import f
from datar.base import sin, pi
from datar.tibble import tibble
from datar.dplyr import mutate, if_else
from plotnine import ggplot, aes, geom_line, theme_classic
df = tibble(x=numpy.linspace(0, 2 * pi, 500))
(
df
>> mutate(y=sin(f.x), sign=if_else(f.y >= 0, "positive", "negative"))
>> ggplot(aes(x="x", y="y"))
+ theme_classic()
+ geom_line(aes(color="sign"), size=1.2)
)
```
![example](./example.png)
```python
# very easy to integrate with other libraries
# for example: klib
import klib
from pipda import register_verb
from datar import f
from datar.data import iris
from datar.dplyr import pull
dist_plot = register_verb(func=klib.dist_plot)
iris >> pull(f.Sepal_Length) >> dist_plot()
```
![example](./example2.png)
## Testimonials
[@coforfe](https://github.com/coforfe):
> Thanks for your excellent package to port R (`dplyr`) flow of processing to Python. I have been using other alternatives, and yours is the one that offers the most extensive and equivalent to what is possible now with `dplyr`.
[1]: https://github.com/pwwang/datar-numpy
[2]: https://github.com/pwwang/datar-pandas
[3]: https://img.shields.io/codacy/coverage/0a7519dad44246b6bab30576895f6766?style=flat-square
[4]: https://img.shields.io/codacy/coverage/45f4ea84ae024f1a8cf84be54dd144f7?style=flat-square
[5]: https://pwwang.github.io/datar/
[6]: https://img.shields.io/pypi/v/datar?style=flat-square
[7]: https://pypi.org/project/datar/
[8]: https://img.shields.io/github/v/tag/pwwang/datar?style=flat-square
[9]: https://github.com/pwwang/datar
[10]: https://img.shields.io/github/actions/workflow/status/pwwang/datar/ci.yml?branch=master&style=flat-square
[11]: https://img.shields.io/github/actions/workflow/status/pwwang/datar/docs.yml?branch=master&style=flat-square
[12]: https://img.shields.io/codacy/grade/3d9bdff4d7a34bdfb9cd9e254184cb35?style=flat-square
[13]: https://app.codacy.com/gh/pwwang/datar
[14]: https://img.shields.io/codacy/coverage/3d9bdff4d7a34bdfb9cd9e254184cb35?style=flat-square
[15]: https://pwwang.github.io/datar/reference-maps/ALL/
[16]: https://pwwang.github.io/datar/notebooks/across/
[17]: https://pwwang.github.io/datar/api/datar/
[18]: https://img.shields.io/pypi/v/datar-numpy?style=flat-square
[19]: https://img.shields.io/pypi/v/datar-pandas?style=flat-square
[20]: https://img.shields.io/pypi/dm/datar?style=flat-square
[21]: https://github.com/tidyverse/dplyr