Formula Prompt

This library let's you define formulas that you can later evaluate in your command line. I use this library for school work that requires repetitive calculations or calculations needing a computer.

Example

Here I define two formulas. Notice the @register_formula(...) decorator that registers the formulas with the library.

from formula_prompt import *

@register_formula([NumInput("side length")])
def volume_of_cube(s):
  return s ** 3

@register_formula([NumInput("length"), NumInput("width")])
def area_of_rectangle(length, width):
  return length * width

Now that the library has registered the formulas, I can launch the prompt.

launch_prompt()

The prompt lets you pick a formula and evaluate it.

0:	area_of_rectangle
1:	volume_of_cube
2:	quit
Pick a formula:
>>> 1
Input side length:
>>> 3
volume_of_cube:
27.0

For more examples, look at the /examples folder on GitHub.

How to use this library

1. Install the library by running: pip install formula-prompt

2. Write your formulas (see example above).

3. Add the @register_formula(...) decorator (see below).

4. Call launch_prompt().

Using @register_formula(...)

@register_formula(...) is a decorator that takes in a few parameters.

Allowed formula inputs

You can specify three types of inputs.

• NumInput: For inputs that accepts a single floating-point number.

• IntInput: For inputs that accept a single integer.

• ListInput: For inputs that accept a list of floating-point numbers.

You can use optional=True to allow skipping the input (this will pass None to your function).

Here's an example.

@register_formula([
    IntInput("first optional input", optional=True),
    NumInput("second non-optional input")
])
def some_funtion(first_integer_input, second_float_input):
    ...

You can also make a custom input type by creating a class that inherits from Inputs. See inputs.py.