gokart 0.1.20

A wrapper of luigi. This make it easy to define tasks.

.. note::

For the latest source, discussion, etc, please visit the
`GitHub repository <https://github.com/m3dev/gokart>`_


# gokart

[](https://travis-ci.org/m3dev/gokart)

A wrapper of the data pipeline library "luigi".


## Getting Started
Run `pip install gokart` to install the latest version from PyPI. [Documentation](https://gokart.readthedocs.io/en/latest/) for the latest release is hosted on readthedocs.

## How to Use
Please use gokart.TaskOnKart instead of luigi.Task to define your tasks.


### Basic Task with gokart.TaskOnKart
```python
import gokart

class BasicTask(gokart.TaskOnKart):
def requires(self):
return TaskA()

def output(self):
# please use TaskOnKart.make_target to make Target.
return self.make_target('basic_task.csv')

def run(self):
# load data which TaskA output
texts = self.load()

# do something with texts, and make results.

# save results with the file path {self.workspace_directory}/basic_task_{unique_id}.csv
self.dump(results)
```

### Details of base functions
#### Make Target with TaskOnKart
`TaskOnKart.make_target` judge `Target` type by the passed path extension. The following extensions are supported.

- pkl
- txt
- csv
- tsv
- gz
- json
- xml

#### Make Target for models which generate multiple files in saving.
`TaskOnKart.make_model_target` and `TaskOnKart.dump` are designed to save and load models like gensim.model.Word2vec.
```python
class TrainWord2Vec(TaskOnKart):
def output(self):
# please use 'zip'.
return self.make_model_target(
'model.zip',
save_function=gensim.model.Word2Vec.save,
load_function=gensim.model.Word2Vec.load)

def run(self):
# make word2vec
self.dump(word2vec)
```

#### Load input data
##### Pattern 1: Load input data individually.
```python
def requires(self):
return dict(data=LoadItemData(), model=LoadModel())

def run(self):
# pass a key in the dictionary `self.requires()`
data = self.load('data')
model = self.load('model')
```

##### Pattern 2: Load input data at once
```python
def run(self):
input_data = self.load()
"""
The above line is equivalent to the following:
input_data = dict(data=self.load('data'), model=self.load('model'))
"""
```


#### Load input data as pd.DataFrame
```python
def requires(self):
return LoadDataFrame()

def run(self):
data = self.load_data_frame(required_columns={'id', 'name'})
```