'dict' object has no attribute 'has_key'
Solution 1:
has_key was removed in Python 3. From the documentation:
- Removed
dict.has_key()– use theinoperator instead.
Here's an example:
if start not in graph:
return None
Solution 2:
In python3, has_key(key) is replaced by __contains__(key)
Tested in python3.7:
a = {'a':1, 'b':2, 'c':3}
print(a.__contains__('a'))