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Python 通过range初始化list set 等

"""

01:range()函数调查

02:通过help()函数调查range()函数功能

03:Python中的转义字符

04:使用start、step、stop的方式尝试初始化list、tuple、set等

05:使用len()获取list、set、tuple的长度

"""

help(range)

tempRange = range(1,100,2)

print("type(tempRange): " + str(type(tempRange)))

print("tempRange: " + str(tempRange))

tempStr = ""

for i in range(5):  # 注意 输出0到4,包括0和4但不包括5.

    tempStr += (" " + str(i) + " ")

print("for i in range(5) " + tempStr) #for i in range(5)  0  1  2  3  4 

tempStr = ""

for i in range(20,0,-2):

    tempStr += (" " + str(i) + " ")

# 注意看输出不包括0

print("for i in range(20,0,-2) " + tempStr)

"""

for i in range(20,0,-2)  20  18  16  14  12  10  8  6  4  2 

"""

tempStr = ""

for i in [1,2,3]:

    tempStr += (" " + str(i) + " ")

# for i in [1,2,3]  1  2  3 

print("for i in [1,2,3] " + tempStr)

tempStr = ""

for i in "Hello world!":

    tempStr += (" " + str(i) + " ")

# for i in "Hello world!"  H  e  l  l  o     w  o  r  l  d  ! 

print("for i in \"Hello world!\" " + tempStr)

print(list(range(5,10))) # 默认步长1,输出:[5, 6, 7, 8, 9]不包括10

print(list(range(0,10,2))) #输出:[0, 2, 4, 6, 8]

print(list(range(10,0,2))) #输出:[]

print(list(range(10,0,-2))) #输出:[10, 8, 6, 4, 2]

# 尝试使用start、step、stop的方式尝试初始化list、tuple、set等

# print(list(1,9,1)) # TypeError: list() takes at most 1 argument (3 given)

# print(set(1,9,1)) # TypeError: set expected at most 1 arguments, got 3

# print(tuple(1,9,1)) # TypeError: tuple() takes at most 1 argument (3 given)

tempList = list(range(0,10,1));

print("list(range(0,10,1)): " + str(tempList))

tempSet = set(range(0,10,1))

print("list(set(0,10,1)): " + str(tempSet))

tempTuple = tuple(range(0,10,1))

print("list(tuple(0,10,1)): " + str(tempTuple))

tempDic = {"num":1}

print("len(list) :" + str(len(tempList))) # len(list) :10

print("len(set) :" + str(len(tempSet))) # len(set) :10

print("len(tuple) :" + str(len(tempTuple))) # len(tuple) :10

print("len(dic) :" + str(len(tempDic))) # len(dic) :1

# list.append [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 'b']

tempList.append('b')

print("list.append " + str(tempList))

# set.add {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 'a'}

tempSet.add('a')

print("set.add " + str(tempSet))