A first glance at Python and Jupyter

1. Hello World

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print('Hello World')

2. Print the 'help' for a particular function (try also using the IPython shell)

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Some useful to get help in Jupyter Notebook:

  • Hold Shift + Tab over a function inside a code cell.
  • Function name with a question mark after it.

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3. IPython Magic Commands

The magics we are going to use the most: %%time, %%timeit, and %matplotlib. More info about magics here.

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3. Importing Python modules

To use an external module in Python you can import it into your script by using the import statement.

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import math #imports the whole module. It requires to use the prefix "math." before calling each function
from math import * #imports all functions and variable within the current namespace (it does not require to use the prefix)
from math import cos, pi #imports only the specific functions and variables listed

Try using the different import options to describe the following expression:

    x = cos(2 *pi)

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x = math.cos(2 * math.pi)
x = cos(2 * pi)


1. Define a function that returns the sum of two random numbers

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import random

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def sumTwoRandomNumbers():
    a = random.random()
    b = random.random()
    c = a+b
    print ('a: ', a, ' b: ', b)
    return c

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2. Define a function that returns the sum of two given numbers

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def sumTwoGivenNumbers(a, b):
    c = a+b
    return c

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sumTwoGivenNumbers(23, 7)

3. Define a function that returns the sum of multiple given numbers

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def sumMultipleNumbers(*args):
    c = sum(args)
    return c

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4. Define a function that returns sum or the average of a variable set of numbers

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def opMultipleNumbers(*args, **kwargs):
    if kwargs.get("operation") == "sum":
         c = sum(args)
    if kwargs.get("operation") == "avg":
         c = sum(args)/len(args)
    return c

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1. Define a function that returns a list of numbers that sum up to 1

  • Generate a list of random numbers
  • Sum up all the numbers in the list
  • Take each number in the initial list and divide it by the sum of all numbers
  • Print the new list
  • Sum up all the values in the new list. It should sum up to 1

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randomNumbers = [random.random() for i in range(1,10)]
s = sum(randomNumbers)
r = [ i/s for i in randomNumbers ]
print (r)

[0.02770880546317565, 0.15676907789403854, 0.002290709060239855, 0.014333832439627468, 0.31363690061092536, 0.17574429881851422, 0.04481370109223432, 0.14866960184950107, 0.11603307277174349]

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