一、数字类型整数:int浮点数:float注:python不同于其它语言,int不区分short、int、long类型,只有一种类型int;浮点数不区分float与double类型,只有一种类型float,在python中float就表示double注:1/2得到的结果是0.5,1//2的结果只取整数部分,即结果为0二、各进制的表示与转换十进制:数字前面不加任何字母,表示十进制...
PEP 485: A function for testing approximate equality PEP 485 adds the math.isclose() and cmath.isclose() functions which tell whether two values are approximately equal or “close” to each other. Whether or not two values are considered close is determined according to given absolute and rela...
x =5y =3# 算术表达式result = x + y *2-4# 比较表达式is_equal = x == y# 逻辑表达式is_greater = x > yandy !=0 注意: 在编写表达式时,需要注意运算符的优先级和结合性。可以使用括号来明确指定运算顺序。 变量和数据类型指南 在Python中,变量用于存储数据,并且每个变量都有一个特定的数据类型。了...
PEP 485: A function for testing approximate equality PEP 485 adds the math.isclose() and cmath.isclose() functions which tell whether two values are approximately equal or “close” to each other. Whether or not two values are considered close is determined according to given absolute and rela...
浮点型 float,用c中的double实现,sys.float_info, 因此Python中无单双精度区分 复数complex, z.real, z.imag 整除/ : 结果总是整数,哪怕除数、被除数不是整数,而且结果总是趋向负无穷大,-1/2=-1 0的0次幂:pow(0,0) =1, 0**0=1 NaN: not a number , INF:无穷大,-inf +inf , float('nan')...
(float_amount):labels=['Decimal','Float']values=[1,float_amount]explode=(0.1,0)plt.pie(values,explode=explode,labels=labels,autopct='%1.1f%%')plt.axis('equal')plt.show()defmain():amount=Decimal('10.50')float_amount=decimal_to_float(amount)draw_pie_chart(float_amount)if__name__=='_...
importmatplotlib.pyplotaspltimportnumpyasnpdefShow_Fig(X,Y,x, y, r):theta = np.arange(0,2* np.pi,0.01)x = x + r * np.cos(theta)y = y + r * np.sin(theta)fig = plt.figure()axes = fig.add_subplot(111)axes.plot(x, y)axes.plot(X, Y,"...
>>> WTF() == WTF() # two different instances can't be equal False >>> WTF() is WTF() # identities are also different False >>> hash(WTF()) == hash(WTF()) # hashes _should_ be different as well True >>> id(WTF()) == id(WTF()) True...
assertEqual(divide(6, 2), 3) self.assertRaises(ZeroDivisionError, divide, 6, 0) if __name__ == '__main__': unittest.main() 4.2.2 测试覆盖率分析与持续集成 确保代码充分测试的一个关键指标是测试覆盖率。使用coverage等工具可以帮助测量代码被执行测试的比例。而持续集成(CI)则是在每次提交后自动...
| | Parameters | --- | threshold : float, optional (0.0 by default) | Feature values below or equal to this are replaced by 0, above it by 1. | Threshold may not be less than 0 for operations on sparse matrices. | | copy : boolean, optional, default True | set to False to pe...