PCEP 认证准备的 Python 元组和列表提示

# creating a list of numbers
numbers = [1, 2, 3, 4, 5]
# modifying the list by changing the fourth element
numbers[3] = 10
print(numbers)
# output: [1, 2, 3, 10, 5]

# creating a tuple of colors
colors = ("red", "green", "blue")
# trying to modify the tuple by changing the second element
colors[1] = "yellow" 
# this will result in an error as tuples are immutable

# creating a list of fruits
fruits = ["apple", "banana", "orange"]

# creating a tuple of colors
colors = ("red", "green", "blue")

# adding a new fruit to the end of the list
fruits.append("mango")
print(fruits)
# output: ["apple", "banana", "orange", "mango"]

# removing a fruit from the list
fruits.remove("banana")
print(fruits)
# output: ["apple", "orange", "mango"]

# trying to add a fruit to the end of the tuple
fruits.append("mango")
# this will result in an error as tuples are immutable

# trying to remove a fruit from the tuple
fruits.remove("banana")
# this will also result in an error

# importing the timeit module
import timeit

# creating a list and a tuple with 10 elements
numbers_list = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
numbers_tuple = (1, 2, 3, 4, 5, 6, 7, 8, 9, 10)

# testing the time it takes to iterate through the list
list_time = timeit.timeit('for num in numbers_list: pass', globals=globals(), number=100000)
print("time taken for list: ", list_time)
# output: time taken for list: 0.01176179499915356 seconds

# testing the time it takes to iterate through the tuple
tuple_time = timeit.timeit('for num in numbers_tuple: pass', globals=globals(), number=100000)
print("time taken for tuple: ", tuple_time)
# output: time taken for tuple: 0.006707087000323646 seconds

# creating a list of groceries
grocery_list = ["milk", "bread", "eggs", "chicken"]
# adding a new item to the grocery list
grocery_list.append("bananas")

# creating a tuple of weekdays
weekdays = ("monday", "tuesday", "wednesday", "thursday", "friday")
# trying to add a new day to the tuple
weekdays.append("saturday")
# this will result in an error as tuples cannot be modified after creation

# importing the sys module
import sys

# creating a list with one million elements
numbers_list = list(range(1000000))
# checking the memory usage of the list
list_memory = sys.getsizeof(numbers_list)
print("memory usage for list: ", list_memory)
# output: memory usage for list:  9000112 bytes

# creating a tuple with one million elements
numbers_tuple = tuple(range(1000000))
# checking the memory usage of the tuple
tuple_memory = sys.getsizeof(numbers_tuple)
print("memory usage for tuple: ", tuple_memory)
# output: memory usage for tuple: 4000072 bytes

# creating a list of numbers
numbers = [1, 2, 3, 4, 5]
# iterating through the list and checking if a number is present
for num in numbers:
    if num == 3:
        print("number 3 is present in the list")
# output: number 3 is present in the list

# creating a tuple of colors
colors = ("red", "green", "blue")
# iterating through the tuple and checking if a color is present
for color in colors:
    if color == "yellow":
        print("yellow is one of the colors in the tuple")
# this will not print anything as yellow is not present in the tuple

# creating a list of even numbers
numbers = [2, 4, 6, 8, 10]
# using the len() function to get the length of the list
print("length of the list: ", len(numbers))
# output: length of the list: 5
# using the in and not in operators to check if a number is present in the list
print(12 in numbers)
# output: false
print(5 not in numbers)
# output: true

# creating a tuple of colors
colors = ("red", "green", "blue")
# using the max() function to get the maximum element in the tuple
print("Maximum color: ", max(colors))
# output: Maximum color: red
# using the in and not in operators to check if a color is present in the tuple
print("yellow" in colors)
# output: False
print("green" not in colors)
# output: False