Python的内置数据类型

# coding  = utf-8print("内置的数据类型")print("真值测试（if，while等的条件测试）")cond = Noneif not cond:    print("None在条件测试中为False")cond = Falseif not cond:    print("False在条件测试中为False")cond = 0if not cond:    print("整数0在条件测试中为False")cond = 0.0if not cond:    print("浮点数0.0在条件测中为False")cond = ''if not cond:    print("空字符串在条件测试中为False")cond = ()if not cond:    print("()在条件测试中为False")cond = (1)if cond:    print("非空()在条件测试中为True")cond = []if not cond:    print("[]在条件测试中为False")cond = [2, 3, 4]if cond:    print("非空[]在条件测试中为True")cond = {}if not cond:    print("空{}在条件测试中为False")cond = {"code": "IF1701", "name": "jacky"}if cond:    print("非空{}在条件测试中为True")class CondClass:    def __init__(self):        self.name = "没有定义__boolean()或__len__()"cond = CondClass()if cond:    print(cond.name, "的条件测试为True")class CondClassBoolean:    def __init__(self):        self.name = "定义了__bool__()方法且返回False"    def __bool__(self):        return Falsecond = CondClassBoolean()if not cond:    print(cond.name, "的条件测试为False")class CondClassLen:    def __init__(self):        self.name = "定义了__len__方法且返回0"    def __len__(self):        return 0cond = CondClassLen()if not cond:    print(cond.name, "的条件测试为False")print("逻辑运算符and, or, not")x = Truey = Trueprint("True and True is", x and y)print("True or True is", x or y)x = Falsey = Falseprint("False and False is", x and y)print("False or False is", x or y)x = Falsey = Trueprint("False and True is", x and y)print("False or True is", x or y)print("比较操作符")x = 10y = 20z = 20print("下面的两个表达式效果相同")print("x < y <= z is", x < y <= z)print("(x < y) and (y <= z) is", (x < y) and (y <= z))print("is和is not，测试的是对象地址是否一样。")cond1 = CondClass()cond2 = CondClass()print("cond1 is cond2 的测试结果是", cond1 is cond2)cond1 = cond2print("cond1 is cond2 的测试结果是", cond1 is cond2)x = 132y = 132print("x的地址是%s, y的地址是%s, x is y的条件测试结果是%s" % (hex(id(x)), hex(id(y)), x is y))print()print("数字类型，int， float， complex")x = 110y = 10print("x = %d, y = %d" % (x, y))print("x + y = %d" % (x + y))print("x - y = %d" % (x - y))print("x * y = %d" % (x * y))print("x / y = %d" % (x / y))print("121 / y = %f" % (121 / y))print("pow(2,10) = %d" % (pow(2, 10)))print("2 ** 10 = %d" % (2 ** 10))print()print("整数的操作")x = -37print("x = %d" % (x))print("转换为二进制，不包含符号位 bin(x) = %s" % (bin(x)))print("转换为二进制，不包含符号位 x.bit_length() = %s" % (x.bit_length()))print("int.from_bytes(b'\\x00\\x10') = %d" % (int.from_bytes(b'\x00\x10', byteorder='big')))  # 相当于二进制00000000 00010000print("int.from_bytes(b'\\x00\\x10') = %d" % (int.from_bytes(b'\x00\x10', byteorder='little')))  # 相当于二进制00001000 00000000()顺序与00000000 00010000相反print()print("浮点数的其他方法")print("(-20.0).is_integer() = %s" % ((-20.0).is_integer()))print("(230.001).is_integer() = %s" % ((230.001).is_integer()))print("float.hex(3470.0) = %s" % (float.hex(3470.0)))print("float.fromhex('0x3.a7p10') = %f" % (float.fromhex('0x3.a7p10')))print("数字类型的Hash算法")print("hash(100) = %s" % (hash(100)))print("hash(-100) = %s" % (hash(-100)))  # 负数的hash值也是有符号数print("hash(200.120) = %s" % (hash(200.120)))print("hash(-200.120) = %s" % (hash(-200.120)))print()print("序列类型list, tuple, range")list = [10, 20, 30, 40, -10, -20, -15, 15, 200]print("list = %s" % (list))print("(-15 in list) = %s" % (-15 in list))print("(1000 in list) = %s" % (1000 in list))print("(-15 not in list) = %s" % (-15 in list))print("(1000 not in list) = %s" % (1000 in list))list2 = [20, 30, 100, 120, -120, -300, -15]print("list2 = %s" % (list2))print("list + list2 = %s" % (list + list2))list3 = list + list2print("list3 = %s" % (list3))print("list3中第2个到20个，步长为2， list3[2:20:2] = %s" % (list3[2:20:2]))print("-15在列表中出现的次数， list3.count(-15) = %d" % (list3.count(-15)))print("[[]]*3 = %s" % ([[]] * 3))  ### [[],[],[]]lists = [[] for i in range(3)]print("[[] for i in range(3)] = %s" % (lists))print("不可修改序列类型tuple")lists = tuple([1, 3, 4, 10])print("tuple序列类型 = ", (lists))#print(list(range(2, 30)))#print("list(range(5,20)) = %s, 最大值为19" % (list(range(5, 20))))print("字符串数据类型")print("单引号", '允许嵌入"双引号"')print("双引号", "允许嵌入'单引号'")
print("三引号", '''三个单''引号你可以写多行''', """三个双引号dd同样可以写多行dd点点滴滴""")      ##三引号是什么样子？？？字符串中间''代表'
str = "hard work beats A TAlent"print("首字母大写，(%s).capitalize() = %s" %(str, str.capitalize()))print("casefold()和lower()的差别。。。。。。")print('"ß".casefold() =', "ß".casefold())print('"ß".lower() =', "ß".lower())print("('%s').center(50,'a') = %s" %(str, str.center(50, 'a')))str = "hard work beats A TAlent"print("'%s'.encode('utf-8') = %s" %(str, str.encode('utf-8')))print("字符串的函数太多，将另外单独处理。。。。。。。。")