PyChecko 1.3.0

MicroFramework to compose instances in execution time

# PyChecko [](https://travis-ci.org/viniciusfeitosa/pychecko)

The PyChecko is a MicroFramework to compose a instance in execution time by rules predefined.

# Example:

There are some [examples](example/).

# Installation:

```
pip install pychecko
```

# Getting started

Inside the directory application...

## Defining class to be used

Our example has two modules, the `app.py` and the `lib.py`.
Inside the `lib.py` there is a method to apply over a class.

```python
# lib.py
def bar(self):
self.email = '[e-mail]'
```

Inside the `app.py` there are a method to apply over the class instance too.
Take a look in the code comments to understand the logic

```python
# app.py
import lib # inside lib has a method bar with the attribute email definition
from pychecko import Pychecko


# There is another method bar with a different definition to the attribute email
def bar(self):
self.email = '[e-mail]'


# Class A definition
class A:
def __init__(self, first_name, last_name):
# There are just two attributes
self.first_name = first_name
self.last_name = last_name

# And just the method foo
def foo(self):
print('{first_name} {last_name}: {email}'.format(
first_name=self.first_name,
last_name=self.last_name,
email=self.email)) # There is a attribute that is defined just in the bar


# the main logic
if __name__ == '__main__':
# Instantiate the class A
a = A('FirstName', 'LastName')
# pass the instance variable to PyChecko
pycheck = Pychecko(a)
# Add the methods that you want apply
pycheck.add(
bar,
[a.first_name == 'FirstName', a.last_name == 'LastName'] # Two bool conditions
)
pycheck.add(
lib.bar,
[a.first_name != 'FirstName' or a.last_name != 'LastName'] # One bool condition
)

# running PyChecko and get the modified instance
a = pycheck.execute

a.bar()
a.foo() # The result will be: FirstName LastName: '[e-mail]'
```

## Pychecko with bulk insert

```python
# app.py
from pychecko import Pychecko


# Method bar definition outside the class
def bar(self):
self.email = '[e-mail]'


# Method foo definition outside the class
def foo(self):
print('{first_name} {last_name}: {email}'.format(
first_name=self.first_name,
last_name=self.last_name,
email=self.email)) # attribute that is defined just in the bar


# Class A definition
class A:
def __init__(self, first_name, last_name):
# There are just two attributes
self.first_name = first_name
self.last_name = last_name


# the main logic
if __name__ == '__main__':
# Instantiate the class A
a = A('FirstName', 'LastName')
# pass the instance variable to PyChecko
pycheck = Pychecko(a)

# Add the methods that you want apply

# Two bool conditions
pycheck.bulk_add(
[
bar,
foo,
]
[True]
)

# running PyChecko and get the modified instance
a = pycheck.execute

a.bar()
a.foo() # The result is: FirstName LastName: '[e-mail]'
```

## Pychecko Using Classes

```python
from pychecko import PycheckoComponent

# Creating a pycheko component
class MyComponentA(PycheckoComponent):

# is_applied is required for the PychecoComponents
# It's responsible to identify if all class methods
# should be applied in an instance
def is_applied(self):
return True

def bar(self):
self.email = '[e-mail]'


class MyComponentB(PycheckoComponent):

def is_applied(self):
return True

def name_changer(self):
self.first_name = 'john doe'
```

```python
# app.py
import lib # inside lib has a method bar with the attribute email definition
from pychecko import PycheckoClassModifier


# There is another method bar with a different
# definition to the attribute email
def bar(self):
self.email = '[e-mail]'


# Class A definition
class A:
def __init__(self, first_name, last_name):
# There are just two attributes
self.first_name = first_name
self.last_name = last_name

# And just the method foo
def foo(self):
print('{first_name} {last_name}: {email}'.format(
first_name=self.first_name,
last_name=self.last_name,
email=self.email)) # attribute that is defined just in the bar


# the main logic
if __name__ == '__main__':
# Instantiate the class A
instance = A('FirstName', 'LastName')
# pass the instance variable to PyCheckoClassModifier
# whit the classes that should be applied
pycheck = PycheckoClassModifier(instance, [
lib.MyComponentA(), # This implements bar()
lib.MyComponentB(), # This implements name_changer()
])

# running PyChecko and get the modified instance
a = pycheck.execute

a.bar()
a.name_changer()
a.foo() # The result is: John Doe LastName: '[e-mail]'

```

## Applying instance validation

Another possible option is validate the instance integrity.

```python
# app.py

'''
create a list with the name methods that must be
in the instance after execute the Pychecko
'''
instance_signature [
'method_a',
'method_b',
'method_c',
]

# In the Pychecko declaration, send the list in the optional parameter
a = A('value1', 'value2')
pycheck = Pychecko(a, signature=instance_signature)
# ...

'''
At final, if all methods that you sent in the list
to Pychecko are in the instance, the instance will be returned
using the `execute` property.

If the instance does't respect the signature will the thrown the
Exception InvalidSignatureClassError
'''
a = pycheck.execute

# ...
```

# Next Features

* Check signature at method level