counter

I'm trying to solve a Rosalind basic problem of counting nucleotides in a given sequence, and returning the results in a list. For those ones not familiar with bioinformatics it's just counting the number of occurrences of 4 different characters ('A','C','G','T') inside a string. I expected collections.Counter to be the fastest method (first because they claim to be high-performance, and second because I saw a lot of people using it for this specific problem). But to my surprise this method is the slowest ! I compared three different methods, using timeit and running two types of experiments:

See below, why does the implementation of += blow away a key in my original counter? >>> c = Counter({'a': 0, 'b': 0, 'c': 0}) >>> c.items() [('a', 0), ('c', 0), ('b', 0)] >>> c += Counter('abba') >>> c.items() [('a', 2), ('b', 2)] I think that's impolite to say the least, there is quite a difference between "X was counted 0 times" and "we aren't even counting Xs". It seems like collections.Counter is not a counter at all, it's more like a multiset. But counters are a subclass of dict and we're allowed to construct them with zero or negative values: Counter(a=0, b=-1) . If it's actually a "bag

How would I go about counting the words in a sentence? I'm using Python. For example, I might have the string: string = "I am having a very nice 23!@$ day. " That would be 7 words. I'm having trouble with the random amount of spaces after/before each word as well as when numbers or symbols are involved. 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

I have the following simple script where I am running a loop and want to maintain a COUNTER . I am unable to figure out why the counter is not updating. Is it due to subshell thats getting created? How can I potentially fix this? #!/bin/bash WFY_PATH=/var/log/nginx WFY_FILE=error.log COUNTER=0 grep 'GET /log_' $WFY_PATH/$WFY_FILE | grep 'upstream timed out' | awk -F ', ' '{print $2,$4,$0}' | awk '{print "http://domain.com"$5"&ip="$2"&date="$7"&time="$8"&end=1"}' | awk -F '&end=1' '{print $1"&end=1"}' | ( while read WFY_URL do echo $WFY_URL #Some more action COUNTER=$((COUNTER+1)) done ) echo

Caution: question still applies to for…of loops.> Don't use for…in to iterate over an Array , use it to iterate over the properties of an object. That said, this I understand that the basic for…in syntax in JavaScript looks like this: for (var obj in myArray) { // ... } But how do I get the loop counter/index ? I know I could probably do something like: var i = 0; for (var obj in myArray) { alert(i) i++ } Or even the good old: for (var i = 0; i < myArray.length; i++) { var obj = myArray[i] alert(i) } But I would rather use the simpler for-in loop. I think they look better and make more sense.