1#使用__metaclass__(元类)的高级python用法2classSingleton2(type):3def__init__(cls,name,bases,dict):4super(Singleton2,cls).__init__(name,bases,dict)5cls._instance=None6def__call__(cls,*args,**kw):7ifcls._instance is None:8cls._instance=super(Singleton2,cls).__call__(*args,**...
Python program to check if a variable is either a Python list, NumPy array, or pandas series# Importing pandas package import pandas as pd # Importing numpy package import numpy as np # Creating a list l = [1, 2, 3, 4, 5] # Creating a numpy array arr = np.arra...
When I run this, the output is exactly what’s expected. 当我运行它时,输出正好是预期的。 Often we need to know the shape of an array or the number of elements in an array. 通常我们需要知道数组的形状或数组中元素的数量。 You can check the shape of an array using shape. 可以使用shape...
array([cos(rad), sin(rad)]) return c_res def sq3(c): # take the cubic root of a complex number, return a complex number rad = arctan(c[1]/c[0]) # range from -pi/2 to pi/2 # rad should be from -pi to pi if c[0]>0 and c[1]>0: rad = rad elif c[0]>0 and ...
Listing2-4Creating TensorswithArbitrary Dimensions 正如我们可以用 Python 列表构建张量一样,我们也可以用 NumPy 数组构建张量。在将 NumPy 代码与 PyTorch 进行交互时,这一功能非常方便。清单 2-5 演示了使用 NumPy 创建张量。 In [1]: a = torch.tensor(numpy.array([[0.1,0.2],[...
if c.issupper(): return True return False def check_lower_exist(m_str): for c in m_str: if c.islower(): return True return False def main(): m_str = input('请输入字符:') m_str_len=len(m_str) # 1只有数字 print( check_number_exist(m_str)) ...
尽管Python 有bool类型,但它在布尔上下文中接受任何对象,例如控制if或while语句的表达式,或者作为and、or和not的操作数。为了确定一个值x是truthy还是falsy,Python 会应用bool(x),它返回True或False。 默认情况下,用户定义类的实例被视为真值,除非实现了__bool__或__len__。基本上,bool(x)...
Check(x)||PyBytes_Check(x)){constchar*string;if(PyByteArray_Check(x))string=PyByteArray_AS_...
. def valid_chain(self, chain): """ check if a bockchain is valid """ ... def resolve_conflicts(self): """ Resolve conflicts between blockchain's nodes by replacing our chain with the longest one in the network. """ ...下面这一行，我们初始化了一...
contiguousarray(img)pred,useTime=predict(img)det=pred[0]p,s,im0=None,'', img0ifdetisnotNoneandlen(det):# 如果有检测信息则进入det[:,:4]=scale_coords(img.shape[1:],det[:,:4],im0.shape).round()# 把图像缩放至im0的尺寸number_i=0# 类别预编号detInfo=[]for*xyxy,conf,clsin...