lazy-graph 0.3.2

lazy graph framework

lazy-graph

lazy-graph is python package for lazy evaluation, with enhancement for updating values of upstream and copying the entire lazy graph.

Install

Copy or link this folder directly. Or use pip to obtain the distribution pip install lazy_graph.

Documents

Simple example

from lazy import Root, Node


def add(a, b):
    print(f"calculating {a} + {b}")
    return a + b


print("create nodes")
a = Root(1)
b = Root(2)
c = Node(add, a, b)
print("get the value")
print(f"c is {c()}")

create nodes
get the value
calculating 1 + 2
c is 3

Update upstream

from lazy import Root, Node


def add(a, b):
    print(f"calculating {a} + {b}")
    return a + b


print("create nodes")
a = Root(1)
b = Root(2)
c = Node(add, a, b)
print("get the value")
print(f"c is {c()}")
print("get the value again")
print(f"c is {c()}")
print("update upstream")
a.reset(4)
print("get the new value")
print(f"c is {c()}")

create nodes
get the value
calculating 1 + 2
c is 3
get the value again
c is 3
update upstream
get the new value
calculating 4 + 2
c is 6

Normal argument or keyword argument are also available

from lazy import Root, Node


def add(a, b, c, d):
    print(f"calculating {a} + {b} + {c} + {d}")
    return a + b + c + d


print("create nodes")
a = Root(1)
c = Root(3)
z = Node(add, a, 2, c=c, d=4)
print("get the value")
print(f"c is {z()}")

create nodes
get the value
calculating 1 + 2 + 3 + 4
c is 10

Copy the lazy graph

from lazy import Root, Node, Copy


def add(a, b):
    print(f"calculating {a} + {b}")
    return a + b


print("create nodes")
a = Root(1)
b = Root(2)
c = Node(add, a, b)
print("get the value")
print(f"c is {c()}")

print("copy lazy graph")
copy = Copy()
new_a = copy(a)
new_b = copy(b)
new_c = copy(c)

print("get the new value")
print(f"new c is {new_c()}")

print("reset value")
a.reset(4)
new_a.reset(8)
print("get the old value and new value")
print(f"c is {c()}, new c is {new_c()}")

create nodes
get the value
calculating 1 + 2
c is 3
copy lazy graph
get the new value
new c is 3
reset value
get the old value and new value
calculating 4 + 2
calculating 8 + 2
c is 6, new c is 10