Nuke python script to connect each selected node's 0th input to the nearest node.

connect_to_closest.py

"""
# Add to menu.py
import connect_to_closest
nuke.toolbar('Nuke').addCommand('Edit/Node/Connect Multiple', 'connect_to_closest.run()', 'meta+shift+y', shortcutContext=2)
"""

import nuke
import math


def get_closest_node(node):
    # Return the closest node to node
    distances = {}
    for n in nuke.allNodes():
        if n.name() == node.name():
            continue
        distance = math.sqrt( 
            math.pow( (node.xpos() - n.xpos()), 2 ) + math.pow( (node.ypos() - n.ypos()), 2 )
        )
        distances[n.name()] = distance
    return nuke.toNode(min(distances, key=distances.get))
        

def run():
    for node in nuke.selectedNodes():
        closest = get_closest_node(node)
        print "{0} : {1}".format(node.name(), closest.name())
        node.connectInput(0, closest)


if __name__=="__main__":
    run()

Hello!
There are actually some built-in functions for this.

• If you select a bunch of nodes and press Ctrl+D that will disconnect the inputs of each node.
• If you instead press Ctrl+Shift+X that will extract each node from the pipe it is connected to.

Also this gist got merged into my dag module, I think I made some updates and improvements since.