- lis1 = [1, 2, 3]
- lis2 = [4, 5, 6]
- lis1
- [1, 2, 3]
- lis2
- [4, 5, 6]
- import numpy as np
- # np.array? 相当于 pycharmd 的 ctrl + 鼠标左键
- # 创建一维的 ndarray 对象
- arr = np.array([1, 2, 3])
- print(arr, type(arr))
- [1 2 3] <class 'numpy.ndarray'>
- # 创建二维的 ndarray 对象
- print(np.array([1, 2, 3], [4, 5, 6]))
- [[1 2 3]
- [4 5 6]]
- # 创建三维的 ndarray 对象
- print(np.array([[1, 2, 3], [4, 5, 6], [7, 8, 9]]))
- [[1 2 3]
- [4 5 6]
- [7 8 9]]
- arr = np.array([[1, 2, 3], [4, 5, 6]], dtype = np.float32)
- print(arr)
- [[1. 2. 3.]
- [4. 5. 6.]]
- print(arr.T)
- [[1. 4.]
- [2. 5.]
- [3. 6.]]
- print(arr.dtype)
- float32
- arr = arr.astype(np.int32)
- print(arr.dtype)
- print(arr)
- int32
- [[1 2 3]
- [4 5 6]]
- print(arr.size)
- 6
- print(arr.ndim)
- 2
- print(arr.shape)
- (2, 3)
- loc(通过行标签取值)
- iloc(类似于 numpy 数组取值)
来源: http://www.bubuko.com/infodetail-3162383.html