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List and Dictionary

List

Command Description
mylist.append('x') Add single item at last of list (changes original list)
mylist.extend(list2) Append whole list at last of list (changes original list)
mylist.insert(pos, elem) Insert elem at pos of list1
mylist.remove(elem) Removes first found elem from list1; gives error if not found
mylist.index(elem) Returns index of elem
mylist.index(elem, i, j) Searches and returns index of elem from mylist[i: j]
mylist.pop(index) Removes elem at position index, else removes last item if index not given
mylist.count(elem) Returns count of elem in the list
mylist.sort(key, reverse=True/False) Key is optional user defined function
new_list = sorted(mylist, reverse=False, key=method_name) unlike sort method, it returns a new
mylist2 = mylist1.copy() Copy list1 to list2
mylist.clear() same as del mylist[:]
mylist.reverse() reverse all items of mylist
filter(method, mylist) Returns iterable for each item of list1 for which 'method' returns true
zip(mylist, mylist2) Zip both lists upto shorter list
max(mylist) Returns max valued item of mylist
min(mylist) Returns min valued item of the list
any(mylist) True if any one of the list item is true; in case of dict, it considers keys only
all(mylist) True if any all of the list items are true; in case of dict, it considers keys only
enumerate(mylist, start)

mylist = [1, 2, 55, 52, 23]
for key, val in enumerate(mylist, 5):
     print(key, val)
5 1
6 2
7 55
8 52
9 23

Dictionary

Command Description
dict.fromkeys(mylist) New dictionary with 'list_items: None' key value pair
mydict.get(key, value2) Return value of given key, and if key not found, returns value2
mydict.popitem() Returns and remove arbitrary key: value pair
mydict.pop(key) Remove key: value
mydict.keys() List of all keys of mydict
mydict.values() List of all values of mydict
mydict.update(k2=v2, k3=v3..) Updating dictionary, if key present update value else add new key:value pair
new_dict = sorted(mydict) Sorted by keys