Python ing list instance analysis and python ing instance analysis

Python ing list instance analysis and python ing instance analysis

This example describes the python ing list. Share it with you for your reference. The specific analysis is as follows:

List ing is a very useful method. By applying a function to each element in the list to convert data, you can use a policy or method to traverse and compute each element.

For example:
Copy codeThe Code is as follows: params = {"server": "mpilgrim ",\
"Database": "master ",\
"Uid": "sa ",\
"Pwd": "secret "\
}
Print ["% s = % s" % (k, params [k]) for k in params. keys ()]
Print ';'. join (["% s = % s" % (k, params [k]) for k in params. keys ()])

The returned result is:
Copy codeThe Code is as follows: ['uid = sa ', 'pwd = secret', 'database = Master', 'server = mpilgrim']
 
We can also improve the conversion of tuples into strings and use the join function method.
Copy codeThe Code is as follows: 'uid = sa; pwd = secret; database = master; server = mpilgrim'
(The join function is used not only for tuples but also for lists. The function is string-based)
In contrast to join, split converts a string to a metagroup.
See the following applications.
Copy codeThe Code is as follows: str = 'server = mpilgrim; uid = sa; database = master; pwd = secret '</span> </pre> str. split (';')
['Server = mpilgrim', 'uid = sa ', 'database = Master', 'pwd = secret']
>>> Str. split (';', 1)
['Server = mpilgrim', 'uid = sa; database = master; pwd = secret ']
>>> Str. split (';', 2)
['Server = mpilgrim', 'uid = sa ', 'database = master; pwd = secret']

List ing case:
Copy codeThe Code is as follows: >>>> li = [1, 9, 8, 4]
>>> [Elem * 2 for elem in li] 1
[2, 18, 16, 8]
>>> Li
[1, 9, 8, 4]

I hope this article will help you with Python programming.