Operators and Operands

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Floor Divsion or Integer division //



In [27]:

    
1//2









    Out[27]:





0



In [28]:

    
#should equal 33.33
100//3









    Out[28]:





33



In [6]:

    
#should not equal 0, but it does
59//60









    Out[6]:





0

True division /



In [9]:

    
1/2









    Out[9]:





0.5



In [10]:

    
100/3









    Out[10]:





33.333333333333336



In [11]:

    
59/60









    Out[11]:





0.9833333333333333

Modulo %

Yields the remainder from the division of the first arg by the second. Basically, for simple calculations - returns the remainder. It can be used to determine divisibilty. Is 25 divisible by 5?



In [29]:

    
25 % 5









    Out[29]:





0



In [22]:

    
23 % 5









    Out[22]:





3



In [38]:

    
nums = [x for x in range(0,100)]

for entry in nums:
    if not entry % 5 :
        print(entry)

Square **

Unlike other programming languages, Python uses ** and not ^



In [23]:

    
5 ** 2 # or 5 squared









    Out[23]:





25



In [26]:

    
nums = [0,1,2,3,4,5]
nums_squared = [element ** 2 for element in nums] # list comprehension
nums_squared









    Out[26]:





[0, 1, 4, 9, 16, 25]

Data Types

Numeric Types: ints, floats, complex
Text Sequence Types: str (already saw this)
Sequence Types: list, tuple, range (coming up)
Mapping Types: dicts (coming up)
Binary Sequence Types: bytes, bytearray, memoryview
Iterator Types (Advanced Python)
Generator Types (Advanced Python)
Set Types (Advanced Python)

ints are whole number integers like, 1, 93874, -4



In [44]:

    
this_is_an_int = 9
nums = [2,2,2,2,2,2,2]

type(nums)









    Out[44]:





list

Control Flow and Compound Statements

if
for
while
try
with



In [12]:

    
x = 1
if x < 100:
    print('X is less than 100')









    



X is less than 100



In [14]:

    
x = 1000
if x > 100:
    print('X is greater than 100')









    



X is greater than 100



In [17]:

    
x = int(input('Please enter a number'))
if x < 0:
    print('X is a negative number')
elif x == 0:
        print('x is 0')
else:
    print('x is a positive number')









    



Please enter a number0
x is 0

There can be no elif and the final else is optional. Note for people with a different language background, Python doesn't have a switch or case statement

For

Python iterates over items of any sequence



In [18]:

    
words = ['cat', 'dog', 'alligator', 'pirate']
for w in words:
    print(w, len(w))









    



cat 3
dog 3
alligator 9
pirate 6



In [51]:

    
var1 = "this is sstring"
for char in var1:
    print(hex(ord(char)))



In [49]:

    
help(ord)









    



Help on built-in function ord in module builtins:

ord(c, /)
    Return the Unicode code point for a one-character string.

While

convention: while true:



In [ ]:

    
while True:

References

https://docs.python.org/3.5/whatsnew/2.2.html?highlight=integer%20division



In [ ]: