A KeyError generally means the key doesn’t exist. So, are you sure the path key exists? From the official python docs: exception KeyError Raised when a mapping (dictionary) key is not found in the set of existing keys. For example: So, try to print the content of meta_entry and check whether path exists or not. Or, you can do:
Yes, it is a hash mapping or hash table. You can read a description of python’s dict implementation, as written by Tim Peters, here. That’s why you can’t use something ‘not hashable’ as a dict key, like a list: You can read more about hash tables or check how it has been implemented in python and why it is implemented that … Read more
There are dictionary comprehensions in Python 2.7+, but they don’t work quite the way you’re trying. Like a list comprehension, they create a new dictionary; you can’t use them to add keys to an existing dictionary. Also, you have to specify the keys and values, although of course you can specify a dummy value if … Read more
You’ll want a Map<String, String>. Classes that implement the Map interface include (but are not limited to): HashMap LinkedHashMap Hashtable Each is designed/optimized for certain situations (go to their respective docs for more info). HashMap is probably the most common; the go-to default. For example (using a HashMap): type of animal
Usually, a Python dictionary throws a KeyError if you try to get an item with a key that is not currently in the dictionary. The defaultdict in contrast will simply create any items that you try to access (provided of course they do not exist yet). To create such a “default” item, it calls the … Read more
As indicated by the other answers, the error is to due to k = list[0:j], where your key is converted to a list. One thing you could try is reworking your code to take advantage of the split function: Note that if you are using Python 3.x, you’ll have to make a minor adjustment to … Read more
in is the intended way to test for the existence of a key in a dict. If you wanted a default, you can always use dict.get(): and if you wanted to always ensure a default value for any key you can either use dict.setdefault() repeatedly or defaultdict from the collections module, like so: but in … Read more
Python 3.7+ or CPython 3.6 Dicts preserve insertion order in Python 3.7+. Same in CPython 3.6, but it’s an implementation detail. or Older Python It is not possible to sort a dictionary, only to get a representation of a dictionary that is sorted. Dictionaries are inherently orderless, but other types, such as lists and tuples, are … Read more
Python 3.7+ or CPython 3.6 Dicts preserve insertion order in Python 3.7+. Same in CPython 3.6, but it’s an implementation detail. or Older Python It is not possible to sort a dictionary, only to get a representation of a dictionary that is sorted. Dictionaries are inherently orderless, but other types, such as lists and tuples, are … Read more
Python 3.7+ or CPython 3.6 Dicts preserve insertion order in Python 3.7+. Same in CPython 3.6, but it’s an implementation detail. or Older Python It is not possible to sort a dictionary, only to get a representation of a dictionary that is sorted. Dictionaries are inherently orderless, but other types, such as lists and tuples, are … Read more