Generate the points style string necessary to add points to a shape in drawio

create_drawio_pts.py

import numpy as np

def pt_str(x,y):
    return f'[{x:.2f}, {y:.2f}]'

# SET THESE TO THE NUMBER OF POINTS YOU NEED
top = 0
left = 0
right = 13
bottom = 0

pts = []

if top:
    xs = np.linspace(0, 1, top)
    y = 0
    pts += [pt_str(x,y) for x in xs]

if bottom:
    xs = np.linspace(0, 1, bottom)
    y = 1
    pts += [pt_str(x,y) for x in xs]

if left:
    x = 0
    ys = np.linspace(0, 1, left)
    pts += [pt_str(x,y) for y in ys]

if right:
    x = 1
    ys = np.linspace(0, 1, right)
    pts += [pt_str(x,y) for y in ys]

pts_str = ','.join(pts)
print(f'points=[{pts_str}]')

Thanks.
It helped me a lot. Now I can create a box out of an image and connect at these points.

Thank for sharing your response and code. Here's a slightly modified version of this code.

The centered option:

In many cases, for example when creating logic circuit diagrams, I need the waypoints to be centered in the edges and exclude the vertice end-points. This can be set to False to include the vertex.

import numpy as np

def drawio_connections(top=0, bottom=0, left=0, right=0, centered=True):
    def pt_str(x,y):
        return f'[{x:.2f},{y:.2f}]'

    def get_points(x):
        ls = np.linspace(0, 1, x+2 if centered else x)
        return ls[1:-1] if centered else ls

    pts = [pt_str(x,0) for x in get_points(top)]
    pts += [pt_str(x,1) for x in get_points(bottom)]
    pts += [pt_str(0,y) for y in get_points(left)]
    pts += [pt_str(1,y) for y in get_points(right)]
    return f'points=[{",".join(pts)}];'

drawio_connections(top=1,bottom=4,left=3)

gives:

points=[[0.50,0.00],[0.20,1.00],[0.40,1.00],[0.60,1.00],[0.80,1.00],[0.00,0.25],[0.00,0.50],[0.00,0.75]];

This is what I get If I apply it to a parallelogram (representing a Multiplexer). Exactly what I wanted!

Both very cool and helpful solutions! Thank you for sharing!

So, I also added some code. And plese be kind, I'm not into Python. 😄

import numpy as np

def drawio_connections(top=0, bottom=0, left=0, right=0, centered=True, mode="CSV", perimeter=False):
    def pt_str(x,y,mode):
      if mode == "CSV":
        if perimeter == True:
          return f'[{x:.2f},{y:.2f},1]'
        else:
          return f'[{x:.2f},{y:.2f}]'
      elif mode == "XML":
        if perimeter == True:
          return f'<constraint x="{x:.2f}" y="{y:.2f}" perimeter="1" />'
        else:
          return f'<constraint x="{x:.2f}" y="{y:.2f}" />'
      else:
        return ""

    def get_points(x):
        ls = np.linspace(0, 1, x+2 if centered else x)
        return ls[1:-1] if centered else ls

    pts = [pt_str(x,0,mode) for x in get_points(top)]
    pts += [pt_str(x,1,mode) for x in get_points(bottom)]
    pts += [pt_str(0,y,mode) for y in get_points(left)]
    pts += [pt_str(1,y,mode) for y in get_points(right)]
    
    if mode == "CSV":
      return f'points=[{",".join(pts)}];'
    elif mode == "XML":
      returnval = '\n'.join(pts)
      return f'{returnval}'
    else:
      return ""

print(drawio_connections(top=1,bottom=1,left=1,right=1,mode="XML"))

This script has two more options:

String mode, can be set to CSV or XML. CSV leads to the standard behaviour you already implemented. XML gives you the coordinates as XML structure to directly use them in shape definitions.

Gives

<constraint x="0.50" y="0.00" />
<constraint x="0.50" y="1.00" />
<constraint x="0.00" y="0.50" />
<constraint x="1.00" y="0.50" />

Minor important
Boolean perimeter, when set to True it adds perimeter as third attribute, which on some shapes interpolates the given point coordinate on the shape edge instead of the outline. Maybe I got it a little bit wrong, documentation was quite confusing on this.

<constraint x="0.25" y="0.00" perimeter="1" />
<constraint x="0.50" y="0.00" perimeter="1" />

or

points=[[0.25,0.00,1],[0.50,0.00,1],[0.75,0.00,1],[0.25,1.00,1],[0.50,1.00,1],[0.75,1.00,1],[0.00,0.25,1],[0.00,0.50,1],[0.00,0.75,1],[1.00,0.25,1],[1.00,0.50,1],[1.00,0.75,1]];

Cheers,
Ben