Numpy

Initialisation

np.zeros()
np.empty()
np.full()
np.arange()

np.asarray() : No copy is performed if the input is already an ndarray with matching dtype and order.

Random

np.random.rand()
np.random.random()
np.random.randint()

Transform

np.reshape(a, newshape, order='C')
np.transpose()

Map

np.sum(x1, x2)
np.prod(x1, x2)

Reduction

np.sum(x)
np.prod(x)
np.argmax(x)
np.nanargmax(x)
np.var(x)
np.nanvar(x)

Compare and set

np.clip()
np.where()

Indexing

np._ix()
# Get the nonzero indices of the given input
np.nonzero()

Slicing

# Slice first n rows
arr[:n, :]
# Slice last n rows
arr[-n:, :]
# Slice first n rows, step m
arr[0:n:m, :]
# ... <=> :,:,:...
arr[:n, ...]

Broadcasting utilities

np.repeat()
np.tile()
np.expand_dims()

Item selection

np.where(idx, x, np.nan)

CSV

np.loadtxt()