我的Python学习之旅2

01--Python安装

Hello World! Third Edition

02--嵌套循环

# This outer loop runs 3 iterations with the values 5, 6, 7
for multiplier in range(5, 8):
    # This inner loop prints a single table
    for i in range(1, 11):
        print(i, "x", multiplier, "=", i * multiplier)
    print()

numLines = int(input('How many lines of stars do you want? '))
numStars = int(input('How many stars per line? '))
for line in range(0, numLines):
    for star in range(0, numStars):
        print('* ', end='')
    print()

numBlocks = int(input('How many blocks of stars do you want? '))
numLines = int(input('How many lines in each block? '))
numStars = int(input('How many stars per line? '))
for block in range(0, numBlocks):
    for line in range(0, numLines):
        for star in range(0, numStars):
            print('* ', end='')
        print()
    print()

numBlocks = int(input('How many blocks of stars do you want? '))
for block in range(1, numBlocks + 1):
    # Formulas for number of lines and stars
    for line in range(1, block * 2):
        for star in range(1, (block + line) * 2):
            print('* ', end='')
        print()
    print()

numBlocks = int(input('How many blocks of stars do you want? '))
for block in range(1, numBlocks + 1):
    print('block =', block)  # Displays variables
    for line in range(1, block * 2 ):
        for star in range(1, (block + line) * 2):
            print('* ', end='')
        print('  line =', line, 'star =', star)
    print()

print("\tDog \tBun \tKetchup\tMustard\tOnions")
count = 1
for dog in [0, 1]:  # dog loop
    for bun in [0, 1]:  # bun loop
        for ketchup in [0, 1]:  # ketchup loop
            for mustard in [0, 1]:  # mustard loop
                for onion in [0, 1]:
                    print("#", count, "\t", end='')
                    print(dog, "\t", bun, "\t", ketchup, "\t", end='')
                    print(mustard, "\t", onion)  # onion loop
                    count = count + 1

# Lists calories for each part of the hot dog
dog_cal = 140
bun_cal = 120
ket_cal = 80
mus_cal = 20
onion_cal = 40

print("\tDog \tBun \tKetchup\tMustard\tOnions\tCalories")  # Prints headings
count = 1
for dog in [0, 1]:  # `dog` is the outer loop
    # Nested loops
    for bun in [0, 1]:
        for ketchup in [0, 1]:
            for mustard in [0, 1]:
                for onion in [0, 1]:
                    # Calculates calories in the inner loop
                    total_cal = (bun * bun_cal)+(dog * dog_cal) + \
                        (ketchup * ket_cal)+(mustard * mus_cal) + \
                             (onion * onion_cal)
                    print("#", count, "\t", end='')
                    print(dog, "\t", bun, "\t", ketchup, "\t", end='')
                    print(mustard, "\t", onion, end='')
                    print("\t", total_cal)
                    count = count + 1

03--列表与字典

#字符串列表
color = ["blue","pink","yellow"]
#数字列表
number = [1,3,5,6,9]
#空列表
blank = []
#在空列表中添加元素,需要用append()
#append追加，在事物末尾添加某个东西，会把元素添加到列表的末尾
blank.append("Blue")
print(blank)
#再添加另外一个元素
blank.append("Yellow")
print(blank)
#列表·可以包含任何内容，列表中的元素数据类型无需相同
list = [1,3,"Blue",4,"Yellow"]
#获取列表的元素
#按索引获取，索引从0开始
print(list[0])#获取的为单个元素
#一次性从列表中获取多个元素，叫作列表切片
print(list[0:2])#获取的元素个数为2-0为2个
print(list[1:2])#获取的元素个数为2-1为1个，但是获取的类型是新的列表
#分片简写
print(list[:2])#冒号前面没有数字，获取第一个元素与索引之间的所有元素（不包括索引）
print(list[2:])#从起始到最后一个（指定索引到最后一个）
print(list[:])#获取所有元素
#修改元素
list[0] = "Pink"
print(list)
#添加元素，在列表添加元素有3种方法
#append()在列表末尾添加元素
#extend()在列表末尾添加多个元素
#insert()在列表某个位置插入元素
list.append("2")
list.extend(["Black",6,9])
print(list)
list.insert(2,"Blue520")#插入的元素占用了索引，后续所有元素索引都会后移一位
print(list)
list.append(["Red",5])#append和extend的区别
print(list)
#从列表中删除元素
#也有3种方法
#remove()从列表中删除选中的元素，然后丢掉
#del 利用索引从列表中删除元素
#pop()可以删除列表中最后一个元素，也可以获取这个元素
list.remove("Blue520")#这里只能删除单个元素或列表？
print(list)
del list[1]#这里也只能删除单个元素或列表
print(list)
a = list.pop()#把list最后一个元素删除并赋值给a
print(list)
print(a)
list.pop(1)#按索引删除某个元素
print(list)
#in关键字
#要在列表中查找某元素，使用in关键字
if 'Pink' in list:
    print("Found 'Pink' in list")
else:
    print(" didn't find 'Pink' in list")
'a' in list
#删除某个元素
if 'Pink' in list:
    list.remove('Pink')
print(list)
#查找索引
if 'Black' in list:
    print(list.index('Black'))
#列表排序sort()
#如果列表中是字符串，按照字母表顺序排列，如果数字，从小到大排列
number = [1,3,2,9,7,9,6,4,8,2,2]
number.sort()
print(number)
#逆序排列reverse
number.reverse()
print(number)
#另一种排序sorted(),sorted()函数会返回原列表的一个有序副本
num1 = [1,8,7,7,1,9,3,2,4,2,8]
num2 = sorted(num1)
print(num1)
print(num2)

#不可变列表，用小括号
num = (2,3,4,4)
#不能在其中添加或删除或排序元素，为元组，一直保持不变
#双重列表
Num = [num1,num2,num]
print(Num)#双重列表
print(Num[0])#单列表
print(Num[0][1])#单列表中的元素