List summary in Python

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A list can be seen as a data structure and a class,

With Help (list) can see its methods, elements of the additions and deletions have a variety of ready-made methods,

Second, the list operation contains the following functions:
1. CMP (List1, List2): Compare elements of two lists
2. Len (list): Number of elements
3. Max (list): Returns the maximum value of the element
4, Min (list): Returns the minimum value of the list element
5. List (seq): Convert tuples to lists

Third, the following methods are included:
1. List.append (obj): Add a new object at the end of the list
2. List.count (obj): Count the number of occurrences of an element in a list
3. List.extend (seq): Append multiple values from another sequence at the end of the list (extend the original list with a new list)
4, List.index (obj): Find the index position of the first occurrence of a value from the list
5. List.insert (index, obj): inserting objects into the list
6, List.pop (Obj=list[-1]): Removes an element from the list (the last element by default), and returns the value of the element
7, List.remove (obj): Removes the first occurrence of a value in a list
8, List.reverse (): Reverse List of elements
9. List.sort ([func]): Sort the original list **python the difference between sort sorted () reverse () reversed () * *

I want to say that append () and extend () obviously have a lot of differences, append directly after the addition, extend equivalent to the expansion.

Four, list and string conversion, the string split () splits it into a list,join () method to synthesize a list of strings;

Split is just the opposite of join, which splits a string into a multi-element list.

Note that the delimiter (";") is completely removed, and it does not appear in any of the elements in the returned list. Split accepts an optional second parameter, which is the number of times to split

>>> li = [' Server=mpilgrim ', ' uid=sa ', ' database=master ', ' Pwd=secret ']
>>> s = ";". Join (LI)
>>> s
' Server=mpilgrim;uid=sa;database=master;pwd=secret '
>>> s.split (";")
[' Server=mpilgrim ', ' uid=sa ', ' database=master ', ' Pwd=secret ']
>>> s.split (";", 1)
[' Server=mpilgrim ', ' Uid=sa;database=master;pwd=secret ']

V. Filtering of the list

>>> li = ["A", "Mpilgrim", "foo", "B", "C", "B", "D", "D"]
>>> [Elem for Elem in Li if Len (elem) > 1]
[' Mpilgrim ', ' foo ']
>>> [Elem for Elem in Li if elem! = "B"]
[' A ', ' Mpilgrim ', ' foo ', ' C ', ' d ', ' d ']
>>> [Elem for Elem in Li if Li.count (elem) = = 1]
[' A ', ' Mpilgrim ', ' foo ', ' C ']

Six, the dictionary parsing (using the list of filter)

>>> params = {"Server": "Mpilgrim", "Database": "Master", "UID": "sa", "pwd": "Secret"}
>>> Params.keys ()
[' Server ', ' uid ', ' database ', ' pwd ']
>>> params.values ()
[' Mpilgrim ', ' sa ', ' master ', ' secret ']
>>> Params.items ()
[(' Server ', ' Mpilgrim '), (' uid ', ' sa '), (' Database ', ' Master '), (' pwd ', ' secret ')]
>>> [k for K, V in Params.items ()]
[' Server ', ' uid ', ' database ', ' pwd ']
>>> [V for K, V in Params.items ()]
[' Mpilgrim ', ' sa ', ' master ', ' secret ']
>>> ["%s=%s"% (k, v) for K, V in Params.items ()]
[' Server=mpilgrim ', ' uid=sa ', ' database=master ', ' Pwd=secret ']

List summary in Python