Kangrui‘s Python Learning Diary 2020-07-21

内容关于用户输入，while循环以及函数
今天所学内容部分需要输入，所以不附运行结果，欢迎大家自己尝试

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以下内容为用户输入和while循环

# input()工作原理，本质是输入字符串
message = input("Tell me something, and I will repeat it back to you: ")
print(message)

name = input("Please enter your name: ")
print("Hello, " + name + "!")

# int()工作原理，本质是将输入视为数值
height = input("How tall are you, in inches? ")
height = int(height)
if height >= 36:
    print("\nYou're tall enough to ride! ")
else:
    print("\nYou'll be able to ride when you're a little older.")

# 求模运算符%，省略

# while循环
current_number = 1
while current_number <= 5:
    print(current_number)
    current_number += 1

# 使用break退出循环
prompt = "\nPlease enter the name of a city you have visited: "
prompt += "\n(Enter 'quit' when you are finished.)"
while True:
    city = input(prompt)
    if city == 'quit':
        break
    else:
        print("I'd love to go to " + city.title() + "!")

# 在循环中使用continue，满足条件时不再执行接下里的程序，进入下一循环
current_number = 0
while current_number < 10:
    current_number += 1
    if current_number % 2 == 0:
        continue
    print(current_number)

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以下内容为函数

# 向函数传递信息
def greet_user(username):
    # 形参username
    print("Hello, " + username.title() + "!")

greet_user('jesse')  # 实参'jesse'

# 传递实参
def describe_pet(animal_type, pet_name):
    print("\nI have a " + animal_type + ".")
    print("My " + animal_type + "'s name is " + pet_name.title() + ".")


describe_pet('hamster', 'harry')  #  位置实参，最基本的是基于实参顺序,不能随意调换
describe_pet(animal_type = 'hamster', pet_name = 'harry')  # 关键字实参，可以换位置


def describe_pet(pet_name, animal_type = 'dog'):  # 包含默认值,且默认值需要在后面
    print("\nI have a " + animal_type + ".")
    print("My " + animal_type + "'s name is " + pet_name.title() + ".")

describe_pet(pet_name = 'willie')

# 返回值
def get_formatted_name(first_name, last_name):
    full_name = first_name + ' ' + last_name
    return full_name.title()

musician = get_formatted_name('jimi', 'hendrix')
print(musician)

# 使参数可选
def get_formatted_name(first_name, middle_name, last_name):
    if middle_name:
        full_name = first_name + ' ' + middle_name + ' ' + last_name
    else:
        full_name = first_name + ' ' + last_name
    return full_name.title()

musician = get_formatted_name('jimi','lee','hendrix')
print(musician)

# 返回字典
def build_person(first_name, last_name):
    person = {'first':first_name, 'last':last_name}
    return person

person = build_person('jimi', 'hendrix')
print(person)


# 传递列表
def greet_users(names):
    for name in names:
        msg = "Hello, " + name.title() + "!"
        print(msg)

usernames = ['hannah', 'ty', 'margot']
greet_users(usernames)

# 禁止函数修改列表
function_name(list_name[:])  #用切片表示法[:]创建列表的副本

# 传递任意数量的实参
    # 使用形参名*names,创建一个空元组，放入所有收到的值
    # 可以和普通实参结合使用

# 将函数存储在模块中，使用import module_name
# 调用模块中的某个函数，module_name.function_name
# 只导入特定的函数，from module_name import function_1,function 2
# 使用as指定别名，from module import function as anothername；import module as anothername
# 导入模块中所有的函数，from module import *