<s>[INST] How would you make a comma-separated string from a list? What would be your preferred way to concatenate strings from a sequence such that between each two consecutive pair a comma is added. That is, how do you map, for instance, [ 'a', 'b', 'c' ] to 'a,b,c'? (The cases [ s ] and [] should be mapped to s and '', respectively.)
I usually end up using something like ''.join(map(lambda x: x+',',l))[:-1], but also feeling somewhat unsatisfied.
Edit: I'm both ashamed and happy that the solution is so simple. Obviously I have hardly a clue as to what I'm doing. (I probably needed "simple" concatenation in the past and somehow memorised s.join([e1,e2,...]) as a shorthand for s+e1+e2+....)
 [/INST] myList = ['a','b','c','d']
myString = ",".join(myList )

This won't work if the list contains numbers.

As Ricardo Reyes suggested, if it contains non-string types (such as integers, floats, bools, None) then do:
myList = ','.join(map(str, myList)) 

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