import numpy as np
def main():
lst=[[1,3,5],[2,4,6]]
print('hello world')
print(type(lst))
np_lst = np.array(lst)
print(type(np_lst))
np_lst = np.array(lst,dtype=np.float)
print(type(np_lst))
print(np_lst.shape)
print(np_lst.ndim)
print(np_lst.dtype)
print(np_lst.itemsize)
print(np_lst.size)
#2 Some Arrays
print(np.zeros([2,4])) #两行四列
print(np.ones([3,5]))
print("Rand:")
print(np.random.rand(2,4))
print(np.random.rand())
print("RandInt:")
print(np.random.randint(1,10,3))
print("Randn:")
print(np.random.randn(2,4))
print("Choice:")
print(np.random.choice([10,20,30,40]))
print("Distribute:")
print(np.random.beta(1,20,100))
#3 numpy Opes
lst=np.arange(1,11).reshape([2,-1])
print("exp:")
print(np.exp(lst))
print("exp2:")
print(np.exp2(lst))
print("sqrt:")
print(np.sqrt(lst))
print("sin:")
print(np.sin(lst))
print("log:")
print(np.log(lst))
if __name__ == '__main__':
main()