Timeit Python. How does it work?
import maxcut as mc
import networkx as nx
G = nx.complete_graph(3)

mc.largest_eigenvector(G)

s = """
    import maxcut as mc
    import networkx as nx
    G = nx.complete_graph(3)
    """
t = timeit.Timer(s, 'mc.largest_eigenvector(G)')

def tmp():
    import maxcut as mc
    import networkx as nx
    G = nx.complete_graph(3)
    mc.largest_eigenvector(G)

t = timeit.Timer(s, 'tmp()')

t = timeit.Timer(setup=s, stmt='mc.largest_eigenvector(G)')