Q:

How to graph nodes on a grid in networkx

Just started learning Network Science and I'm a novice in Python so I've been having a hard time figuring this out even after reading a good bit of the networkx documentation. I need to compare the distance between all the nodes and generate an edge in the event the distance is less than d. 
1) How to I compare node 1 to nodes (2...99) and then compare node 2 to nodes (3...99), etc. If there's a better way to do it than O(n^2) please show me. 
2) How can I use the x,y coordinates stored in node_loc{} to graph each node to a coordinate plane?
import random, math
import matplotlib.pyplot as plt
import numpy as np
import networkx as nx
import pylab

# Calc distance given (x1,x2,y1,y2)
def distance(x1,x2,y1,y2):
    return math.sqrt(((x2-x1)**2)+((y2-y1)**2))

# Generate coordinate value
def coord_val():
    # node needs x and y coordinates (floats) from 0->100
    return random.uniform(0.0,100.0)

def main():
    # The distance that applies to link generation
    d = 20

    # Make a graph and name it
    g = nx.Graph(name = "100x100 Field Random Network")

    # Generate 100 nodes
    for num in range(0,100):

        # generate a dict with the node's location
        node_loc = {'x': coord_val(), 'y': coord_val()}

        # Add node with x,y dict
        g.add_node(num,node_loc)

    # Check node n against node n+1
    for n,d in g.nodes(data=True):
        if n == 99:
            break

        # I don't think this loop is correct
        for rl in g.nodes(data=True):
            # Don't go out of bounds on the loop
            if n == 99:
                break

            # grab coordinates from nodes
            y1=g.node[n]['y']
            x1=g.node[n]['x']
            y2=g.node[n+1]['y']
            x2=g.node[n+1]['x']

            # Check the distance, if < d, generate edge
            if distance(x1,x2,y1,y2) < d:
                # add edge
                g.add_edge(n,n+1)

    # plot
    # draw_random draws it on a plane, but randomly :(
    nx.draw_random(g,node_size=50)

    plt.show()

if __name__ == '__main__':
    main()

A:

Take a look at the networkx random geometric graph generator for an implementation of a graph like you are looking for https://github.com/networkx/networkx/blob/master/networkx/generators/geometric.py#L79
There is an example that shows the output and how to draw it here https://networkx.github.io/documentation/stable/tutorial.html#drawing-graphs

