pamda 2.9.0

Functional programming for python

Pamda

Python wrapper for functional programming in object oriented structures.

Inspired heavily by Ramda.

Documentation for Pamda Functions

https://connor-makowski.github.io/pamda/pamda/pamda.html

Key Features

• Simplified functional programming for python
• Core Functions include:
  • curry arbitrary methods and functions
  • thunkify arbitrary methods and functions
  • pipe data iteratively through n functions
• List based path access and features for nested dictionaries

Setup

Make sure you have Python 3.9.x (or higher) installed on your system. You can download it here.

Installation

pip install pamda

Getting Started

Basic Usage

from pamda import pamda

data={'a':{'b':1, 'c':2}}
# Example: Select data given a path and a dictionary
pamda.path(['a','b'])(data) #=> 1

# See documentation for all core pamda functions at
# https://connor-makowski.github.io/pamda/pamda.html

Curry Usage

from pamda import pamda

# Define a function that you want to curry
def myFunction(a,b,c):
    return [a,b,c]

# You can call pamda.curry as a function to curry your functions
curriedMyFn=pamda.curry(myFunction)

# Inputs can now be passed in an async fashion
# The function is evaluated when all inputs are added
x=curriedMyFn(1,2)
x(3) #=> [1,2,3]
x(4) #=> [1,2,4]

# Each set of inputs returns a callable function
# You can stack inputs on a single line for clean functional programming
curriedMyFn(1,2)(3) #=> [1,2,3]

For enforcing types, pamda relies on type_enforced but curried objects do not play nice with type_enforced objects. To fix this, there is a special curry function, curryType, that enables type_enforced annotations for your curried functions:

>>> from pamda import pamda
>>>
>>> # Pamda CurryTyped
>>> @pamda.curryTyped
... def add(a:int,b:int):
...     return a+b
...
>>> add(1)(1)
2
>>> add(1)(1.5)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/home/conmak/development/personal/pamda/pamda/pamda_curry.py", line 43, in __call__
    results = self.__fnExecute__(*new_args, **new_kwargs)
  File "/home/conmak/development/personal/pamda/venv/lib/python3.10/site-packages/type_enforced/enforcer.py", line 90, in __call__
    self.__check_type__(assigned_vars.get(key), value, key)
  File "/home/conmak/development/personal/pamda/venv/lib/python3.10/site-packages/type_enforced/enforcer.py", line 112, in __check_type__
    self.__exception__(
  File "/home/conmak/development/personal/pamda/venv/lib/python3.10/site-packages/type_enforced/enforcer.py", line 34, in __exception__
    raise TypeError(f"({self.__fn__.__qualname__}): {message}")
TypeError: (add): Type mismatch for typed variable `b`. Expected one of the following `[<class 'int'>]` but got `<class 'float'>` instead.

Thunkify Usage

from pamda import pamda

# Define a function that you want to thunkify
# thunkify can be called as a function or decorator
@pamda.thunkify
def myFunction(a,b,c):
    return [a,b,c]

# The function is now curried and the evaluation is lazy
# This means the function is not evaluated until called
x=myFunction(1,2)
x(3) #=> <pamda.curry_obj object at 0x7fd514e4c820>
x(3)() #=> [1,2,3]

y=x(4)
y() #=> [1,2,4]

Thunkified functions can be executed asynchronously.

from pamda import pamda
import time

@pamda.thunkify
def test(name, wait):
    print(f'{name} start')
    time.sleep(wait)
    print(f'{name} end')
    return wait

async_test_a = pamda.asyncRun(test('a',2))
async_test_b = pamda.asyncRun(test('b',1))
async_test_a.asyncWait()
async_test_c = pamda.asyncRun(test('c',1))

The above code would output:

a start
b start
b end
a end
c start
c end

Pipe

from pamda import pamda

def square(x):
    return x**2

def half(x):
    return x/2

def negate(x):
    return -x

# You can pipe data through multiple functions for clean functional programming
pamda.pipe([square, half, negate])(args=(6,),kwargs={}) #=> -18

Use pamda as a subclass

from pamda import pamda

class myClass(pamda):
    def myFunction(self, a):
        return self.inc(a)

mc=myClass()
mc.myFunction(2) #=> 3

@mc.curry
def addUp(a,b):
    return a+b

addUp(1)(2) #=> 3

Pamda Utils

• Pamda also ships with a few helpful utilities
• Check out the documentation here:
  • https://connor-makowski.github.io/pamda/pamda.html#pamda-utils