docstr: Read graph from adjacency file in which the edge must be unweighted
  the format of each line: v1 n1 n2 n3 ... nk
  :param filename: the filename of input file
docstr_tok: ["Read","graph","from","adjacency","file","in","which","the","edge","must","be","unweighted","the","format","of","each","line",":","v1","n1","n2","n3","...","nk",":","param","filename",":","the","filename","of","input","file"]
code: def read_adjlist(self, filename):
      """Read graph from adjacency file in which the edge must be unweighted
      the format of each line: v1 n1 n2 n3 ... nk
      :param filename: the filename of input file
      """
      self.G = nx.read_adjlist(filename, create_using=nx.DiGraph())
      for i, j in self.G.edges():
          self.G[i][j]["weight"] = 1.0
      self.encode_node()
  
file_path: OpenNE/src/openne/graph.py
imports: import networkx
  import pickle
  import numpy
  import scipy.sparse
label_desc: Use image node_id 4 for calling the Graph obj's underlying member method code with example usage: obj.read_adjlist(filename) without return types