The performance is almost a 100% identical. You can check this out by opening the class in Reflector.net This is the This indexer: public TValue this[TKey key] { get { int index = this.FindEntry(key); if (index >= 0) { return this.entries[index].value; } ThrowHelper.ThrowKeyNotFoundException(); return default(TValue); } set { this.Insert(key, value, false); } } And this … Read more
Could there be any problem if i replace Method-1 by Method-2? No, just use map[key] = value. The two options are equivalent. Regarding Dictionary<> vs. Hashtable: When you start Reflector, you see that the indexer setters of both classes call this.Insert(key, value, add: false); and the add parameter is responsible for throwing an exception, when … Read more
The correct answer is: stop NOT wanting to catch the ValueError. Example Python script returns a boolean if a string is valid json: import json def is_json(myjson): try: json_object = json.loads(myjson) except ValueError as e: return False return True print(is_json(‘{}’)) # prints True print(is_json(‘{asdf}’)) # prints False print(is_json(‘{“age”:100}’)) # prints True print(is_json(‘{‘age’:100 }’)) # prints … Read more
There is actually an option for this in sqlite3. Change the row_factory member of the connection object to sqlite3.Row: conn = sqlite3.connect(‘db’, row_factory=sqlite3.Row) or conn.row_factory = sqlite3.Row This will allow you to access row elements by name–dictionary-style–or by index. This is much more efficient than creating your own work-around.
If you want a simple design, essentially I would do it in a static mapper class. We definitely need more information to help you, but short of that, here is some psuedocode (not production code) that should be a sufficient design pattern. public static class CustomMapper { public static void leadToContact(Lead lead, ID contactID) { … Read more
You can use nones = not all(d.values()) If all values are not None, nones would be set to False, else True. It is just an abstraction though, internally it must iterate over values list.
There is no such limit in place regarding dictionary keys. Since python also has arbitrary precision on numeric types, the only limit you will encounter, string or otherwise, is that of available memory. You can see another post here for a discussion on maximum string length in python 2.
Is there a reason you can’t set the column names on the next line? my_dict = {‘key1’ : [1,2,3], ‘key2’ : [4,5,6], ‘key3’ :[7,8,9]} df = pd.DataFrame.from_dict(my_dict, orient=”index”) df.columns = [‘one’, ‘two’, ‘three’] Should work.
Maps and Sets are not well suited for random access. They are ordered and their length is known, but they are not indexed for access by an order index. As such, to get the Nth item in a Map or Set, you have to iterate through it to find that item. The simple way to … Read more
First, flip the dictionary around into a reverse multidict, mapping each value to all of the keys it maps to. Like this: >>> some_dict = {“firstname”:”Albert”,”nickname”:”Albert”,”surname”:”Likins”,”username”:”Angel”} >>> rev_multidict = {} >>> for key, value in some_dict.items(): … rev_multidict.setdefault(value, set()).add(key) Now, you’re just looking for the keys in the multidict that have more than 1 value. … Read more