There is such a mistake , First, check to see if you use a dictionary , The error message means that the corresponding key value cannot be found .
for example , Given the following dictionary ：
book_dict = {
"price": 500, "bookName": "Python Design ", "weight": "250g"}
If you look up what exists in the dictionary key, The output is normal ：
print(book_dict["price"])
The operation results are as follows ：
If you look up something that doesn't exist in the dictionary key, False report ：
print(book_dict["sdfs"])
As shown above , The error message is KeyError:. For this kind of problem , have access to get() The solution ：
dict.get(key, default)
That is, for the key, Given a default value , If found in the dictionary , Returns... In the dictionary value, Otherwise, the default value is returned .
print(book_dict.get("price", "111"))
print(book_dict.get("sdfs", "hhh"))
The operation results are as follows ：
