Rebind

Inprospect hard-coded constants in some messy code and rebind them on the fly.

Installation

pip install rebind

Usage

from rebind import introspect, rebind, lookup, plookup

Example code:

# example.py
def f(x, y, n=1):
    k = 10
    z = x**n + y**n + k
    return z

def g(x):
    alpha = 42
    return f(x, alpha)

beta = 17
def h(x):
    return beta * x

Introspect constants:

assert introspect(f) == {'example.f.n': 1, 'example.f.k': 10}
assert introspect('example.f') == {'example.f.n': 1, 'example.f.k': 10}
assert introspect(g) == {'example.f.n': 1, 'example.f.k': 10,
                         'example.g.alpha': 42, 'example.f': f}
assert introspect(h) == {'example.beta': 17}

Rebind on the fly:

# Rebind inline constants
f20 = rebind('example.f', {'example.f.k': 20})

# Rebind enclosed constant
h_beta_18 = rebind(h, {'example.beta': 18})

# Recursively rebind g and f
g2 = rebind(g, {'example.f.k': 11, 'example.g.alpha': 43})

Lookup function code, file and line easily:

>>> print lookup(f)
# example.py:5
def g(x):
    alpha = 42
    return f(x, alpha)

>>> plookup('example.A.__init__')
# example.py:31
    def __init__(self, x):
        h = 3
        self.prop = h * x