Python - Count elements in list
PythonListPython Problem Overview
I am trying to find a simple way of getting a count of the number of elements in a list:
MyList = ["a", "b", "c"]
I want to know there are 3 elements in this list.
Python Solutions
Solution 1 - Python
http://docs.python.org/library/functions.html#len">`len()`</a>
>>> someList=[]
>>> print len(someList)
0
Solution 2 - Python
just do len(MyList)
This also works for strings, tuples, dict objects.
Solution 3 - Python
len(myList) should do it.
len works with all the collections, and strings too.
Solution 4 - Python
len()
it will count the element in the list, tuple and string and dictionary, eg.
>>> mylist = [1,2,3] #list
>>> len(mylist)
3
>>> word = 'hello' # string
>>> len(word)
5
>>> vals = {'a':1,'b':2} #dictionary
>>> len(vals)
2
>>> tup = (4,5,6) # tuple
>>> len(tup)
3
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Solution 5 - Python
To find count of unique elements of list use the combination of len() and set().
>>> ls = [1, 2, 3, 4, 1, 1, 2]
>>> len(ls)
7
>>> len(set(ls))
4
Solution 6 - Python
You can get element count of list by following two ways:
>>> l = ['a','b','c']
>>> len(l)
3
>>> l.__len__()
3
Solution 7 - Python
Len won't yield the total number of objects in a nested list (including multidimensional lists). If you have numpy, use size(). Otherwise use list comprehensions within recursion.