Crash course on Python

README.md

Crash course on Python

CommandLineArguments.py

import sys
print(sys.argv[0])  # CommandLineArguments.py
print(sys.argv[1])  # hello
print(sys.argv[2])  # world

#python CommandLineArguments.py hello world

Comments.py

#print("Hello world")

HelloWorld.py

print("Hello world")

Operators.py

# basic arithmetic operators
six     = 4 + 2 # addition
two     = 4 - 2 # subtraction
eight   = 4 * 2 # multiplication
four    = 8 / 2 # division

# intermediate arithmetic operators
nine    = 3 ** 2    # exponent
one     = 9 % 2     # modulus
three   = 23 // 7   # floor division; opposite of modulus

# boolean operators (returns boolean)
a = True & False    # and
b = True | False    # or
c = False ^ True    # xor
d = not True        # negate

# comparison operators (returns boolean)
e = 5 == 0  # is equal to 0
f = 5 != 0  # is not equal to
g = 5 <> 0  # is not equal to
h = 5 > 0   # is greater than
i = 0 < 5   # is lesser than
j = 5 >= 0   # is greater than or equal to
k = 0 <= 5   # is lesser than or equal to

# output
print(six)      # 6
print(two)      # 2
print(eight)    # 8
print(four)     # 4

print(nine)     # 9
print(one)      # 1
print(three)    # 3

print(a)        # False
print(b)        # True
print(c)        # True
print(d)        # False

print(e)        # False
print(f)        # True
print(g)        # True
print(h)        # True
print(i)        # True
print(j)        # True
print(k)        # True

StringAsArray.py

a = "Hello world"

print(a[0]) # prints "H"

print(a[0:1]) # prints "H"
print(a[0:2]) # prints "He"
print(a[0:3]) # prints "Hel"

TypeCasting.py

# integers
x = int(1)   # x will be 1
y = int(2.8) # y will be 2
z = int("3") # z will be 3

# floats
x = float(1)     # x will be 1.0
y = float(2.8)   # y will be 2.8
z = float("3")   # z will be 3.0
w = float("4.2") # w will be 4.2

# strings
x = str("s1") # x will be 's1'
y = str(2)    # y will be '2'
z = str(3.0)  # z will be '3.0'

Variables.py

# numeric
int_variable = 5
float_variable = 2.8
complex_variable = 5j

# string
string_variable = "This works"
string_variable = 'This works too'

# boolean
boolean_variable = True
boolean_variable = False

# output
print(int_variable)
print(float_variable)
print(complex_variable)
print(string_variable)
print(boolean_variable)