Indexing routines

Generating index arrays

unravel_index(indices, shape[, order])	Converts a flat index or array of flat indices into a tuple of coordinate arrays.
diag_indices(n[, ndim])	Return the indices to access the main diagonal of an array.
diag_indices_from(arr)	Return the indices to access the main diagonal of an n-dimensional array.
mask_indices(n, mask_func[, k])	Return the indices to access (n, n) arrays, given a masking function.
tril_indices(n[, k, m])	Return the indices for the lower-triangle of an (n, m) array.
tril_indices_from(arr[, k])	Return the indices for the lower-triangle of arr.
triu_indices(n[, k, m])	Return the indices for the upper-triangle of an (n, m) array.
triu_indices_from(arr[, k])	Return the indices for the upper-triangle of arr.
indices(dimensions[, dtype, sparse])	Return an array representing the indices of a grid.
ix_(*args)	Construct an open mesh from multiple sequences.
nonzero(a)	Return the indices of the elements that are non-zero.
flatnonzero(a)	Return indices that are non-zero in the flattened version of a.
where()	where(condition, [x, y])

Indexing-like operations

choose(a, choices[, out, mode])	Construct an array from an index array and a list of arrays to choose from.
compress(condition, a[, axis, out])	Return selected slices of an array along given axis.
diag(v[, k])	Extract a diagonal or construct a diagonal array.
diagonal(a[, offset, axis1, axis2])	Return specified diagonals.
select(condlist, choicelist[, default])	Return an array drawn from elements in choicelist, depending on conditions.
take(a, indices[, axis, out, mode])	Take elements from an array along an axis.
take_along_axis(a, indices, axis)	Take values from the input array by matching 1d index and data slices.

Inserting data into arrays

fill_diagonal(a, val[, wrap])	Fill the main diagonal of the given array of any dimensionality.
put(a, indices, values[, mode])	Replaces specified elements of an array with given values.
putmask(a, mask, values)	Changes elements of an array based on conditional and input values.
put_along_axis(a, indices, values, axis)	Put values into the destination array by matching 1d index and data slices.
place(arr, mask, vals)	Change elements of an array based on conditional and input values.