吴裕雄--天生自然Numpy库学习笔记：NumPy 从已有的数组创建数组

import numpy as np 

x =  [1,2,3]
a = np.asarray(x)
print (a)

import numpy as np 

x =  (1,2,3)
a = np.asarray(x)
print (a)

import numpy as np 

x =  [(1,2,3),(4,5)]
a = np.asarray(x)
print (a)

import numpy as np 

x =  [1,2,3]
a = np.asarray(x, dtype =  float)
print (a)

import numpy as np 

s =  b'Hello World'
a = np.frombuffer(s, dtype =  'S1')
print (a)

import numpy as np
s =  'Hello World'
a = np.frombuffer(s, dtype =  'S1')
print (a)

import numpy as np 

# 使用 range 函数创建列表对象
list=range(5)
it=iter(list)

# 使用迭代器创建 ndarray
x=np.fromiter(it, dtype=float)
print(x)