In [6]:

    

print('Hello World!')


    

    




Hello World!

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_ = """
language classification
  - types
  - interpreted
  
- python used?
  - youtube, dropbox, linux os utilities
  - https://www.paypal-engineering.com/2014/12/10/10-myths-of-enterprise-python/
  - largest library
- repl
  - python
  - ipython
"""


    

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# this is a comment


    

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# variables
x = 7
print(x)
x = 'apple'
print(x)
del x
print(x)


    

    




7
apple






    




---------------------------------------------------------------------------
NameError                                 Traceback (most recent call last)
<ipython-input-9-da10ae3c19b5> in <module>()
      5 print(x)
      6 del x
----> 7 print(x)

NameError: name 'x' is not defined

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# multiple assignment
x, y = 3,4
print(x,y)


    

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# swapping
y, x = x, y
print(x,y)


    

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x, y = None, None
print(x, y)


    

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# equality - 'is' is not ==
# is  compares references; checking for same object
# ==  calls the __eq__ function, checks for same value
# !=  calls the __ne__ function, checks for same value


    

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# Is it true?
t, f = True, False
print(2 == 2)
print(2 is 2)


    

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x = 100000
y = 100000

i, j = 1, 1

print(i == j)
print(i is j)

print(x == y)
print(x is y)


    

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# conditions
if 2 is 2:
    print('but obviously')

if 'abc' is 'abc':
    print('abc')
    
if 'abc' is not 2:
    print("this will print")
elif 'abc' is 'abc':
    print('elif prints')
else:
    print('not this though')
    
if 2:
    print('truthy baby')
    
if 0:
    print("won't print")
else:
    print("falsy baby")


    

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# lists
empty_list = []
x = [1,2,3,4,5]
x.append(6)
y = list()
y.append(1)
print(x,y)

if x:
    print('truthy baby')
else:
    print ("won't print")
    
if not empty_list:
    print('finally found an empty list, I can retire now')


    

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# index access for lists    
print(x[0])
print(x[1])
print(x[-1]) #negative indices
print(x[2:4])
print(x[1:])
print(x[-1:])
print(x[-3:-1]) #splicing


    

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# hetrogenous lists
hlist = ['apple', True, 42]
print(hlist)


    

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# list comprehension
numbers = range(0,100)

even = [i for i in numbers if i % 2 is 0]
odd = [i for i in numbers if i % 2 is not 0]
variant = [i + 1000 for i in numbers if i % 2 is 0]

print(even, odd, variant, sep='\n\n')


    

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# dictionary
d = {}
d = {'a':'apple', 'b':'ball'} #json if you use double quotes
d = {"a":"apple", "b":"ball"}
print(d)


    

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d['c'] = 'cat'
print(d)


    

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d['x']


    

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print(d.get('b'))
print(d.get('x'))


    

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print(d.get('e', '**'))


    

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for each in range(0,10):
    print(each)


    

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x = 2
while x < 4:
    print('ha')
    x += 1


    

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p = (4,'apple')
print(p[0])
p[0] = 3


    

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def will_boss_give_me_a_raise(x, luck=True, hard_work=10000):
    print(hard_work)
    return True

print(will_boss_give_me_a_raise(3, hard_work=None))
print(will_boss_give_me_a_raise)


    

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def printer(self):
    return 'Kashif works really hard, really!'

class Work:
    pass

Work.__str__ = printer

class HardWork(Work):
    pass


h = HardWork()

print(will_boss_give_me_a_raise(h))


    

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_ = """
#TODO
  - dictionaries
  - iteration
  - default values
- loops
  - for each
  - ranges
- tuples
- printing
- functions
  - optional params
  - argument unpacking
- classes
  - dunder methods
- exceptions
- import this
- advanced
  - reflection
  - decorators
  - generators
  - context manager - with
  - annotations
  - coroutines
"""


    

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