CODEWITHSUNDEEP
pythonlisttuples
SPCode
SPCode

Reputation: 29

Grouping of list of tuples in python

Here's the improved version of your question for Stack Overflow:

I have a program that takes input and displays it in the form of a list. However, I want to take input separately and perform the grouping operation separately because I need two variables: the number of nodes and the edges. I need these two variables for the __init__ function of the Graph class.

Here's the Graph class:

class Graph:

    def __init__(self, num_nodes, edges):
        self.data = [[] for _ in range(num_nodes)]
        for v1, v2 in edges:
            self.data[v1].append(v2)
            self.data[v2].append(v1)

    def __repr__(self):
        return "\n".join(["{} : {}".format(i, neighbors) for (i, neighbors) in enumerate(self.data)])

    def __str__(self):
        return repr(self)

# Example usage:
# g1 = Graph(num_nodes, edges)
# print(g1)

In the code below, the problem is that it performs both operations in a single variable t. I want to separate these operations:

t = list(tuple(map(int, input().split())) for _ in range(int(input('enter number of rows: '))))
print(t)

I need the output to look like this:

enter number of nodes: 3
enter edges:
1 2
3 4
5 6

list of edges:
[(1, 2), (3, 4), (5, 6)]

How can I modify my code to take the number of nodes and edges as separate inputs and store them in separate variables? Here's what I have tried so far:

num_nodes = int(input('enter number of nodes: '))
edges = []
num_edges = int(input('enter number of edges: '))

print('enter edges:')
for _ in range(num_edges):
    edge = tuple(map(int, input().split()))
    edges.append(edge)

print('list of edges:')
print(edges)

When I use this input method, how can I correctly initialize and use the Graph class with these variables? Any suggestions or improvements are welcome!

Upvotes: -1

Views: 60

Answers (1)

hhimko
hhimko

Reputation: 155

If I'm following your question correctly, and all you want is getting back the "enter no of nodes:" input value, then just call len(t) like this:

t = list(tuple(map(int, input("enter edges: ").split())) for r in range(int(input("enter no of nodes: "))))  

print("list of edges: ", end="")
print(t)
print("num_nodes: ", end="")
print(len(t))

With your example values this prints:

enter no of nodes: 3
enter edges: 1 2
enter edges: 3 4
enter edges: 5 6
list of edges: [(1, 2), (3, 4), (5, 6)]
num_nodes: 3

Upvotes: 1

Related Questions