name = 'world'
print('hello ' + name + '!')

a = 1
print('first cell: a = {}'.format(a))

a += 1
print('second cell: a = {}'.format(a))

import numpy as np
from matplotlib import pyplot
%matplotlib inline

x = np.linspace(1E-3, 2 * np.pi)

pyplot.plot(x, np.sin(x) / x)
pyplot.plot(x, np.cos(x))
pyplot.grid()

from IPython.display import Latex
Latex('∫_{-∞}^∞ e^{-x²}dx = \sqrt{π}')

import ipywidgets as w
from IPython.display import display

a = w.IntSlider()
b = w.IntText()
w.jslink((a, 'value'), (b, 'value'))
display(a, b)

print('this code is invisible')

print('this output is invisible')

print('this code is below the output')

print('A')
print('B')
print('C')

print('A')
print('B')
print('C')

d = {
    'a': 1,
    'b': 2,
    'c': 3,
    'd': 4,
    'e': 5,
}

1 / 0

a = {'hello': 'world!'}
a['jello']

import sys

print("hello, world!", file=sys.stderr)