UPDATE The code in this answer was used as a basis for http://github.com/charlotte-ruby/impressionist Try it out It would probably take you less time to code this into your app then it would to pull the data from Analytics using their API. This data would most likely be more accurate and you would not have to … Read more
You can use the recipe that uses collections.Counter and collections.OrderedDict: from collections import Counter, OrderedDict class OrderedCounter(Counter, OrderedDict): ‘Counter that remembers the order elements are first encountered’ def __repr__(self): return ‘%s(%r)’ % (self.__class__.__name__, OrderedDict(self)) def __reduce__(self): return self.__class__, (OrderedDict(self),) words = [“oranges”, “apples”, “apples”, “bananas”, “kiwis”, “kiwis”, “apples”] c = OrderedCounter(words) print(c) # OrderedCounter(OrderedDict([(‘oranges’, 1), … Read more
It is possible to have a counter using the substitute-with-an-expression feature (see :help sub-replace-\=). Unfortunately, since the \= construct allows only expressions, the :let command cannot be used, and therefore, a variable cannot not be set the usual way. However, there is a simple trick to change the value of a variable in expression if that variable … Read more
Here you go with filter df.groupby(‘city’).filter(lambda x : len(x)>3) Out[1743]: city 0 NYC 1 NYC 2 NYC 3 NYC Solution two transform sub_df = df[df.groupby(‘city’).city.transform(‘count’)>3].copy() # add copy for future warning when you need to modify the sub df
Use the Counter.most_common() method, it’ll sort the items for you: >>> from collections import Counter >>> x = Counter({‘a’:5, ‘b’:3, ‘c’:7}) >>> x.most_common() [(‘c’, 7), (‘a’, 5), (‘b’, 3)] It’ll do so in the most efficient manner possible; if you ask for a Top N instead of all values, a heapq is used instead of … Read more
From the source code of collections.py, we see that if we don’t specify a number of returned elements, most_common returns a sorted list of the counts. This is an O(n log n) algorithm. If we use most_common to return k > 1 elements, then we use heapq.nlargest. This is an O(k) + O((n – k) … Read more
OrderedCounter is given as an example in the OrderedDict documentation, and works without needing to override any methods: class OrderedCounter(Counter, OrderedDict): pass When a class method is called, Python has to find the correct method to execute. There is a defined order in which it searches the class hierarchy called the “method resolution order” or … Read more
str.split() without any arguments splits on runs of whitespace characters: >>> s=”I am having a very nice day.” >>> >>> len(s.split()) 7 From the linked documentation: If sep is not specified or is None, a different splitting algorithm is applied: runs of consecutive whitespace are regarded as a single separator, and the result will contain … Read more
The Counter class was added to the module in Python 2.7. You are most likely using Python 2.6 or older. From the collections.Counter() documentation: New in version 2.7. On python 2.5 or 2.6, use this backport instead.
It’s not because collections.Counter is slow, it’s actually quite fast, but it’s a general purpose tool, counting characters is just one of many applications. On the other hand str.count just counts characters in strings and it’s heavily optimized for its one and only task. That means that str.count can work on the underlying C-char array … Read more