AttributeError Problem

[animemaiden]

Hi,

I'm trying to display a graph in Tkinter  that reads a graph from a file and displays it on a panel which the first line in the file contains a number that indicates the number of vertices (n). The vertices are labeled as 0,1,…,n-1. Each subsequent line, with the format u x y v1, v2, …describes that the vertex u is located at position (x,y) with the edges (u,1). (u,v2), and so on.


I'm using Python 3.2.3 and I keep getting this error:

numberOfVertices = int(infile.readline().decode()) # Read the first line from the file
AttributeError: 'str' object has no attribute 'readline'


Here is my code:

from tkinter import * # Import tkinter
from tkinter import filedialog



def displayGraph(canvas, vertices, edges):
    radius = 3
    for vertex, x, y in vertices:
        canvas.create_text(x - 2 * radius, y - 2 * radius, text = str(vertex), tags = "graph")
        canvas.create_oval(x - radius, y - radius, x + radius, y + radius, fill = "black", tags = "graph")

    for v1, v2 in edges:
        canvas.create_line(vertices[v1][1], vertices[v1][2], vertices[v2][1], vertices[v2][2], tags = "graph")

def main():

    infile = filedialog.askopenfilename()

    
    numberOfVertices = int(infile.readline().decode()) # Read the first line from the file
    print(numberOfVertices)

    vertices = []
    edges = []
    for i in range(numberOfVertices):
        items = infile.readline().strip().split() # Read the info for one vertex
        vertices.append([int(items[0]), int(items[1]), int(items[2])])
        for j in range(3, len(items)):
            edges.append([int(items[0]), int(items[j])])            
    
    print(vertices)
    print(edges)
    
    infile.close()  # Close the input file

    window = Tk() # Create a window
    window.title("Display a Graph") # Set title
    
    frame1 = Frame(window) # Hold four labels for displaying cards
    frame1.pack()
    canvas = Canvas(frame1, width = 300, height = 200)
    canvas.pack()
    
    displayGraph(canvas, vertices, edges)
    
    window.mainloop() # Create an event loop

main()