# coding = utf-8
print("内置的数据类型")
print("真值测试（if，while等的条件测试）")
cond = None
if not cond:
print("None在条件测试中为False")
cond = False
if not cond:
print("False在条件测试中为False")
cond = 0
if not cond:
print("整数0在条件测试中为False")
cond = 0.0
if 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 False
cond = 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 0
cond = CondClassLen()
if not cond:
print(cond.name, "的条件测试为False")
print("逻辑运算符and, or, not")
x = True
y = True
print("True and True is", x and y)
print("True or True is", x or y)
x = False
y = False
print("False and False is", x and y)
print("False or False is", x or y)
x = False
y = True
print("False and True is", x and y)
print("False or True is", x or y)
print("比较操作符")
x = 10
y = 20
z = 20
print("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 = cond2
print("cond1 is cond2 的测试结果是", cond1 is cond2)
x = 132
y = 132
print("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 = 110
y = 10
print("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 = -37
print("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 00010000
print("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 + list2
print("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。。。。。。。。")
