Python：在子类中使用父类的字典

Question

I want to use the dictionaries from the parent class "Graph"and use it in the subclass called "Summary".

The dictionaries are nodes, degree, neighbors, histogram, and graph.

The functions in Summary cannot be used when trying to use "graph.(tab completion)", so that is the problem I am running into.

I am new to python and programming in general, so I don't know if what I am trying to do is possible or not.

class Graph:
    '''docstring'''

    def __init__(self, graph):

        d = {}
        d1 = {}
        d2 ={}
        with myfile as f:
            next(f)
            for line in f:
                k, v = line.split()
                d[int(k)] = int(v)
                next(f)

            myfile.seek(0)

            data = [line.strip() for line in myfile]
            d1 = dict(enumerate(data))

            del d1[0]

            d2 = {key: list(map(int, value.split())) for key, value in d1.items()}

            i = 1
            while i <= max(d2.keys()):
                del d2[i]
                i += 2

            neighbors = dict(enumerate(d2.values(), start = 1))


        hist = defaultdict(list)
        for key, values in neighbors.iteritems():
            hist[len(values)].append(key)
        histogram = dict(hist)

        degree = d.values()
        nodes = d.keys()

        self.graph = graph
        self.nodes = nodes
        self.degree = degree
        self.neighbors = neighbors
        self.histogram = histogram

class Summary(Graph):
    def __init__(self, graph):
        Graph.__init__(self, graph)

    def Avg_Connectivity(self):


        return ("Average Node Connectivity:", np.average(self.degree))

    def Max_Connectivity(self):

        return ("Maximum Node Connectivity:" , max(self.degree)),("Node with Maximum Connectivity:", self.nodes[self.degree.index(max(self.degree))]) 

    def Min_Connectivity(self):
        return ("Minimum Node Connectivity:", min(x for x in self.histogram.keys() if x != 0)),("Nodes with Minimum Connectivity", self.histogram[min(x for x in self.histogram.keys() if x != 0)])


if __name__ == '__main__':

    import numpy as np
    from collections import defaultdict
    infile = raw_input("Enter File Name (e.g. e06.gal): ")
    myfile = open(infile, 'r')
    graph = Graph(myfile)

Answer 1

In general, Summary inherits all fields and methods from Graph . So you are able to access self.graph or self.nodes in Summary . Have you tried to access these fields? If it did not work, what was the error?

Answer 2

Per comments, you're not using Summary anywhere. You have a Graph object. A subclass "adds" new methods to an existing class, but they only exist in the new class, not the one you inherit from.

Inheritance is a poor choice for this problem anyway; a "summary" is not a special case of a "graph". You want a separate object that wraps a graph.

class Summary(object):
    def __init__(self, graph):
        self.graph = graph

    def avg_connectivity(self):
        return ("Average Node Connectivity:", np.average(self.graph.degree))

    # ... etc


if __name__ == '__main__':
    import numpy as np
    infile = raw_input("Enter File Name (e.g. e06.gal): ")
    myfile = open(infile, 'r')
    graph = Graph(myfile)
    summary = Summary(graph)

Adjust the other methods to use self.graph rather than properties on self directly. Now summary will have the methods you want.

Some other comments on your code:

• You have very, very long lines. You can wrap anywhere in parentheses, or use temporary variables instead of the same long expression twice.

• Foo_Bar is a very unusual way to style a name; just keep it lowercase.

• Your Graph constructor takes an open file (confusingly named graph ), and then keeps ahold of it as self.graph . You probably don't need to do this.

• Your variable names in general are kind of hard to understand: d vs d1 vs d2 , and hist vs histogram . Comments would help too.

• You should put your import at the top of the file, not in this block at the bottom.

• Does this file format have pairs of lines? Reading that is a little complicated; I sympathize :)