With Python 2.7+, you can use collections.Counter. Otherwise, see this counter receipe. Under Python 2.7+: from collections import Counter input = [‘a’, ‘a’, ‘b’, ‘b’, ‘b’] c = Counter( input ) print( c.items() ) Output is: [(‘a’, 2), (‘b’, 3)]
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
The first one will eventually terminate, even if x doesn’t reach exactly 2.0… because it’ll end up being greater than 2.0, and thus break out. The second one would have to make x hit exactly 1.0 in order to break. It’s unfortunate that the first example uses a step of 0.25, which is exactly representable … Read more
Well, you don’t really need to use methods of Counter in order to count, do you? There’s a += operator for that, which also works in conjunction with Counter. c = Counter() for item in something: if item.has_some_property: c[item.property] += 1 elif item.has_some_other_property: c[item.other_property] += 1 elif item.has_some.third_property: c[item.third_property] += 1
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
I ended up creating my own plugin. Here it is in case this helps anyone: (function($) { $.fn.countTo = function(options) { // merge the default plugin settings with the custom options options = $.extend({}, $.fn.countTo.defaults, options || {}); // how many times to update the value, and how much to increment the value on each … Read more
No jQuery used and is a very clean implementation: Reads from the maxlength attribute. Scales to any number of inputs inside of your container. Automatically finds the next input to focus. No jQuery. http://jsfiddle.net/4m5fg/5/ <div class=”container”> a: <input type=”text” maxlength=”5″ /> b: <input type=”text” maxlength=”5″ /> c: <input type=”text” maxlength=”5″ /> </div> .. var container … Read more
It looks like you may have some nulls in the column. You can drop them with df = df.dropna(subset=[‘item’]). Then df[‘item’].value_counts().max() should give you the max counts, and df[‘item’].value_counts().idxmax() should give you the most frequent value.
select name, @rownum := @rownum + 1 as row_number from your_table cross join (select @rownum := 0) r order by name This part: cross join (select @rownum := 0) r makes it possible to introduce a variable without the need of a seperate query. So the first query could also be broken down into two … Read more
It depends what you mean by “it”. The iterator knows what index it’s reached, yes – in the case of a List<T> or an array. But there’s no general index within IEnumerator<T>. Whether it’s iterating over an indexed collection or not is up to the implementation. Plenty of collections don’t support direct indexing. (In fact, … Read more