Arithmetic Operators
Addition (+), subtraction (-), multiplication (*), and division (/) operators can be used with numbers in Python.
Another operator available is the modulo (%) operator, which returns the integer remainder of the division. dividend % divisor = remainder.
remainder = 14 % 3
print(remainder)
Using two multiplication symbols serves as exponents.
square = 3 ** 2
cube = 3 ** 3
print(square)
print(cube)
Operations with Strings
Python supports concatenating strings using the addition operator:
my_text= "hello" + " " + "world"
print(my_text)
Python also supports multiplying strings to form a string with a repeating sequence:
lol= "ha" * 10
print(lol)
List Operations
Lists can be joined using the addition operator:
even_numbers = [2,4,6,8]
odd_numbers = [1,3,5,7]
all_numbers = odd_numbers + even_numbers
print(all_numbers)
Just as in strings, Python supports forming new lists with a repeating sequence using the multiplication operator:
print([1,2,3] * 3)
Exercise
The target of this exercise is to create two lists called x_list and y_list, which contain 10 instances of the variables x and y, respectively. You are also required to create a list called big_list, which contains the variables x and y, 10 times each, by concatenating the two lists you have created.
x = object()
y = object()
# TODO: change this code
x_list = [x]
y_list = [y]
big_list = []
print("x_list contains %d objects" % len(x_list))
print("y_list contains %d objects" % len(y_list))
print("big_list contains %d objects" % len(big_list))
# testing code
if x_list.count(x) == 10 and y_list.count(y) == 10:
print("Almost there...")
if big_list.count(x) == 10 and big_list.count(y) == 10:
print("Great!")
x = object()
y = object()
# TODO: change this code
x_list = [x] * 10
y_list = [y] * 10
big_list = x_list + y_list
print("x_list contains %d objects" % len(x_list))
print("y_list contains %d objects" % len(y_list))
print("big_list contains %d objects" % len(big_list))
# testing code
if x_list.count(x) == 10 and y_list.count(y) == 10:
print("Almost there...")
if big_list.count(x) == 10 and big_list.count(y) == 10:
print("Great!")
test_output_contains("x_list contains 10 objects")
test_output_contains("y_list contains 10 objects")
test_output_contains("big_list contains 20 objects")
success_msg("Excellent!")