import numpy as np the_array = np.array([49, 7, 44, 27, 13, 35, 71]) an_array = np.where(the_array > 30, 0, the_array) print(an_array) Output: [ 0 7 0 27 13 0 0] 将大于 30 小于 50 的所有元素替换为 0 import numpy as np the_array = np.array([49, 7, 44, ...
usemask:If True, return a masked array loose:If True, do not raise errors for invalid values invalid_raise:If True, an exception is raised if an inconsistency is detected in the number of columns. If False, a warning is emitted and the offending lines are skipped ...
import numpy as np the_array = np.array([49, 7, 44, 27, 13, 35, 71]) an_array = np.where((the_array > 30) & (the_array < 50), 0, the_array) print(an_array) Output: [ 0 7 0 27 13 0 71] 给所有大于 40 的元素加 5 import numpy as np the_array = np.array([49...
my_array[2:6] #This returns everything from index 2 to 6(exclusive)my_array[:6] #This returns everything from index 0 to 6(exclusive)my_array[5:] #This returns everything from index 5 to the end of the array.类似地，我们也可以通过使用 [ ][ ] 或 [,] 在二维数组中选择元素。使用...
Return a 2-D array with ones on the diagonal and zeros elsewhere. Parameters --- N : int Number of rows in the output. M : int, optional Number of columns in the output. If None, defaults to `N`. k : int, optional Index of the...
import numpy as np # create 2D array the_array = np.arange(50).reshape((5, 10)) # row manipulation np.random.shuffle(the_array) # display random rows rows = the_array[:2, :] print(rows) Output: 代码语言:javascript 代码运行次数:0 运行 复制 [[10 11 12 13 14 15 16 17 18 19...
the number of axes (dimensions) of the array. In the Python world, the number of dimensions is referred to as rank. ndarray.shape the dimensions of the array. This is a tuple of integers indicating the size of the array in each dimension. For a matrix with n rows and m columns, shap...
the_array = np.arange(50).reshape((5, 10)) # row manipulation np.random.shuffle(the_array) # display random rows rows = the_array[:2, :] print(rows) 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. Output: [[10 11 12 13 14 15 16 17 18 19] ...
arr_2d=np.array([[1,0,2],[0,3,4],[5,6,0]])rows_without_zeros=arr_2d[~np.any(arr_2d==0,axis=1)]print("Rows without zeros from numpyarray.com:")print(rows_without_zeros) Python Copy Output: 这个例子移除了包含零的行。np.any(arr_2d == 0, axis=1)检查每行是否包含零,~操作...
size # total number of elements 12 >>> a.itemsize # number of bytes of storage per element 8 >>> array( [ [1,2,3], [4,5,6] ] ) array([[1, 2, 3], [4, 5, 6]]) >>> a = _ >>> a.dtype dtype('int32') >>> a.shape (2, 3) >>> array( range(7), float )...