# Bottom Python Editor Bottom Editor offers a standalone editor version at [[https://bottom.ch/editor/]] and a web component embeddable as normal HTML elements after loading the module once. See the [[https://bottom.ch/editor/stable/doc/|public documentation]] for all options. Also see [[~kara]] for a Kara shim on top of bottom-editor. ## Basic Usage Within Dokuwiki, the HTML needs to be embedded into `` tags for verbatim HTML.








print(42)

## Shared Sessions By default, all editors on a page share a single python runtime. Functions defined in one execution are available in all editors afterwards, similar to jupyter notebooks. If you want an editor to have a separate python runtime, use the `session` attribute:



def greet(name):
    print(f'Hi, {name}!')



greet('Harry') # works



greet('Harry') # fails

def greet(name): print(f'Hi, {name}!')

greet('Harry') # works

greet('Harry') # fails ## Turtle Standard Python turtle with a small canvas. Use `layout="split"` to have both canvas and console.



import turtle

t = turtle.Turtle()
t.speed(9)
colors = ['red', 'orange', 'gold', 'green', 'blue', 'purple']
for i in range(90):
    t.pencolor(colors[i % len(colors)])
    t.forward(i * 0.5)
    t.left(59)

import turtle t = turtle.Turtle() t.speed(9) colors = ['red', 'orange', 'gold', 'green', 'blue', 'purple'] for i in range(90): t.pencolor(colors[i % len(colors)]) t.forward(i * 0.5) t.left(59) ## Matplotlib `plt.show()` renders to the canvas.



# Load packages from within python using micropip
import micropip
await micropip.install('matplotlib')

import matplotlib.pyplot as plt
import math

x = [i * 0.1 for i in range(63)]
plt.figure(figsize=(5, 4))
plt.plot(x, [math.sin(v) for v in x], label='sin')
plt.plot(x, [math.cos(v) for v in x], label='cos')
plt.legend()
plt.title('Trigonometric functions')
plt.tight_layout()
plt.show()

# Load packages from within python using micropip import micropip await micropip.install('matplotlib') import matplotlib.pyplot as plt import math x = [i * 0.1 for i in range(63)] plt.figure(figsize=(5, 4)) plt.plot(x, [math.sin(v) for v in x], label='sin') plt.plot(x, [math.cos(v) for v in x], label='cos') plt.legend() plt.title('Trigonometric functions') plt.tight_layout() plt.show() ## OpenCV `cv2.imshow()` renders to the canvas.



# Load packages from within python using micropip
import micropip
await micropip.install('numpy')
await micropip.install('opencv-python')

import numpy as np
import cv2

# Gradient image with a circle
img = np.zeros((300, 300, 3), dtype=np.uint8)
for y in range(300):
    for x in range(300):
        img[y, x] = [x * 255 // 300, y * 255 // 300, 128]
cv2.circle(img, (150, 150), 80, (255, 255, 255), 3)
cv2.putText(img, 'OpenCV', (75, 160), cv2.FONT_HERSHEY_SIMPLEX, 1, (255,255,255), 2)
cv2.imshow('result', img)

# Load packages from within python using micropip import micropip await micropip.install('numpy') await micropip.install('opencv-python') import numpy as np import cv2 # Gradient image with a circle img = np.zeros((300, 300, 3), dtype=np.uint8) for y in range(300): for x in range(300): img[y, x] = [x * 255 // 300, y * 255 // 300, 128] cv2.circle(img, (150, 150), 80, (255, 255, 255), 3) cv2.putText(img, 'OpenCV', (75, 160), cv2.FONT_HERSHEY_SIMPLEX, 1, (255,255,255), 2) cv2.imshow('result', img) ## Installing files You can install files from an URL (with CORS headers if from a different domain!):



with open('gemeinden.csv', 'r') as infile:
    for line in infile:
        tokens = line.split(',')
        town = tokens[0]
        if town == 'Romanshorn':
            print(f'Romanshorn hat {tokens[2]} Einwohner')

with open('gemeinden.csv', 'r') as infile: for line in infile: tokens = line.split(',') town = tokens[0] if town == 'Romanshorn': print(f'Romanshorn hat {tokens[2]} Einwohner') ## Exercises




            Write a function sum_to(n) that returns
            1 + 2 + … + n. Return 0 for
            n ≤ 0.

Write a function sum_to(n) that returns 1 + 2 + … + n. Return 0 for n ≤ 0.