Pathfinding A* algorithm implemented

Pseudocode (https://en.wikipedia.org/wiki/A*_search_algorithm)
function A*(start,goal)
closedset := the empty set    // The set of nodes already evaluated.
openset := {start}    // The set of tentative nodes to be evaluated,
initially containing the start node
came_from := the empty map    // The map of navigated nodes.

g_score[start] := 0    // Cost from start along best known path.
// Estimated total cost from start to goal through y.
f_score[start] := g_score[start] + heuristic_cost_estimate(start, goal)

while openset is not empty
current := the node in openset having the lowest f_score[] value
if current = goal
return reconstruct_path(came_from, goal)

remove current from openset
add current to closedset
for each neighbor in neighbor_nodes(current)
tentative_g_score := g_score[current] + dist_between(current,neighbor)
if neighbor in closedset and tentative_g_score >= g_score[neighbor]
continue

if neighbor not in openset or tentative_g_score < g_score[neighbor]
came_from[neighbor] := current
g_score[neighbor] := tentative_g_score
f_score[neighbor] := g_score[neighbor] +
heuristic_cost_estimate(neighbor, goal)
if neighbor not in openset
add neighbor to openset

return failure

function reconstruct_path(came_from, current_node)
if current_node in came_from
p := reconstruct_path(came_from, came_from[current_node])
return (p + current_node)
else
return current_node