How can I convert the str representation of a dict, such as the following string, into a dict? s = “{‘muffin’ : ‘lolz’, ‘foo’ : ‘kitty’}” I prefer not to use eval. What else can I use? The main reason for this, is one of my coworkers classes he wrote, converts all input into strings. … Read more
Given: >>> d = {‘a’: 1, ‘b’: 2} Which of the following is the best way to check if ‘a’ is in d? >>> ‘a’ in d True >>> d.has_key(‘a’) True 9 s 9 in is definitely more pythonic. In fact has_key() was removed in Python 3.x.
I can’t get to the bottom of this error, because when the debugger is attached, it does not seem to occur. Collection was modified; enumeration operation may not execute Below is the code. This is a WCF server in a Windows service. The method NotifySubscribers() is called by the service whenever there is a data … Read more
I know I can iterate over a map m by, for k, v := range m { … } and look for a key but is there a more efficient way of testing a key’s existence in a map? I couldn’t find the answer in the language spec. 1Best Answer 11 recommended by Go Language
In Python 2.7, I could get dictionary keys, values, or items as a list: >>> newdict = {1:0, 2:0, 3:0} >>> newdict.keys() [1, 2, 3] Now, in Python >= 3.3, I get something like this: >>> newdict.keys() dict_keys([1, 2, 3]) So, I have to do this to get a list: newlist = list() for i … Read more
How would you initialise a static Map in Java? Method one: static initialiser Method two: instance initialiser (anonymous subclass) or some other method? What are the pros and cons of each? Here is an example illustrating the two methods: import java.util.HashMap; import java.util.Map; public class Test { private static final Map<Integer, String> myMap = new … Read more
I have a dictionary where keys are strings, and values are integers. stats = {‘a’: 1, ‘b’: 3000, ‘c’: 0} How do I get the key with the maximum value? In this case, it is ‘b’. Is there a nicer approach than using an intermediate list with reversed key-value tuples? inverse = [(value, key) for … Read more
I set dict2 = dict1. When I edit dict2, the original dict1 also changes. Why? >>> dict1 = {“key1”: “value1”, “key2”: “value2”} >>> dict2 = dict1 >>> dict2[“key2”] = “WHY?!” >>> dict1 {‘key2’: ‘WHY?!’, ‘key1’: ‘value1’} 2 21
What would be a nice way to go from {2:3, 1:89, 4:5, 3:0} to {1:89, 2:3, 3:0, 4:5}? I checked some posts but they all use the “sorted” operator that returns tuples. 3 32
Is there some way of initializing a Java HashMap like this?: Map<String,String> test = new HashMap<String, String>{“test”:”test”,”test”:”test”}; What would be the correct syntax? I have not found anything regarding this. Is this possible? I am looking for the shortest/fastest way to put some “final/static” values in a map that never change and are known in … Read more
