Home/ Questions/Why do i get the trouble with “attributeerror: 'dict' object has no attribute 'has_key'”?
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Adalyn Wilson
  • 26
Asked: 2022-05-18T16:24:02+00:00 In:

Why do i get the trouble with “attributeerror: ‘dict’ object has no attribute ‘has_key’”?

  • 26

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I don’t know what I’m doing wrong, but I’ve already lost a couple of days struggling with this. Here is my command line:

def find_path(graph, start, end, path=[]):
  path = path + [start]
  if start == end:
  return path
  if not graph.has_key(start):
  return None
  for node in graph[start]:
  if node not in path:
  newpath = find_path(graph, node, end, path)
  if newpath: return newpath
  return None

This returns:

dict' object has no attribute 'has_key'

I don’t have any experience with the “attributeerror: ‘dict’ object has no attribute ‘has_key’”. In this case, how should I change?

attributeerror
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2 Answers

  1. Best Answer
    Expert

    The cause:

    The error is on the 5th line, you are using has_key(key) but Python 3.0 does not accept it.

    Solution:

    To solve this error, you have to use __contains__(key) instead of has_key(key)

    We also have checked it in python3.7:

    a = {'a':1, 'b':2, 'c':3}
print(a.__contains__('a'))

    Another solution for this error is using in as below:

    graph={'A':['B','C'],
'B':['C','D']}

print('A' in graph)
>> True

print('E' in graph)
>> False
    • 19

  2. Python 3 removed has_key. From the documentation

    • dict.has_key() has been removed. Instead, use the in operator.

    Here’s an example. 

    if start not in graph:
 return None
    • 12

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