usenix lisa

a = ‘python‘print(‘hello,‘, a or ‘world‘)b = ‘‘print (‘hello,‘, b or ‘world‘)print(‘-----------------------------------‘)Create ListL = [‘Adam‘,95.5,‘Lisa‘,85,‘Bart‘,59]print(‘创建list:‘,L)print(‘-----------------------------------‘)#按照索引访问listprint(‘按照索引访问list:‘,L[3])print(‘-----------------------------------‘)#倒序访问listprint(‘倒序访问list:‘,L[-6])print(‘-----------------------------------‘)#向List添加新元素L.insert(0,‘Paul‘)print(‘向List添加新元素:‘,L)print(‘---------

, emphasizing the four-generation maternal love, the style of character clothes, especially music, is very close to that of the three generations. It is a product that integrates the essence of the four works of this series. I. Role analysis: Many players in the movie version are familiar with the role. Although some of them are not loyal to the original work, I believe that players can set the character to match the character in the first generation of the game. Based on the main plot of

function f can handle the data type.TaskAssuming that the user entered the English name is not standard, not according to the first letter capitalization, subsequent letter lowercase rules, please use the map () function, a list (including a number of nonstandard English names) into a list containing the canonical English name:Input: [' Adam ', ' LISA ', ' BarT ']Output: [' Adam ', ' Lisa ', ' Bart ']" "As

list. If you want to convert all the numbers in this list into strings, usemap()It's easy: >>> list(map(str, [1, 2, 3, 4, 5, 6, 7, 8, 9]))['1', '2', '3', '4', '5', '6', '7', '8', '9'] Exercises:Exploitationmap()Function, which converts invalid English names entered by the user into upper-case letters and other lower-case standard names. Input['adam', 'LISA', 'barT'],Output['Adam', 'Lisa', 'Bart'] def norma

# exercise 1: Use the map function, the user entered the non-standard English name, the first letter capitalized, the other lowercase canonical name.def nomalize (name):Return Name.capitalize ()L1 = ["Adam", "LISA", "BarT"]L2 = List (map (NOMALIZE,L1))Print (L2) #[' Adam ', ' Lisa ', ' Bart '#练习2: the sum () function provided by Python can receive a list and sum. Write a prod () function that receives a lis

Append () and insert ()Add new ElementNow, there are 3 students in the class:>>> L = [' Adam ', ' Lisa ', ' Bart ']Today, the class transferred to a new classmate Paul, how to add new students to the existing list?The first option is to append the new classmate to the end of the list by using the Append () method of the list:>>> L = [' Adam ', ' Lisa ', ' Bart ']>>> l.append (' Paul ')>>> Print L[' Adam ',

, map (Fn_map, L)) print (" \ n ") print (math. SQRT ((3 * 10) * * 2 + (4 * 10) * * 2 + (6 * 10) * * 2 + (8 * 10) * * 2))Note: To import math First, the above code output is as follows:Fn_map-> 3fn_map-> 4fn_sqrt->, 40fn_map-> 6fn_sqrt-> 50.0, 60fn_map-> 8fn_sqrt-> 78.10249675906 654, 80111.80339887498948111.80339887498948The above example, may not be practical, the following is a more practical example, the first letter of each word capitalized, the other letters lowercase.def normalize (name):

parentheses, of course, curly braces is a dictionary.★ There are 2 small details, first:If the list is only 1 digits, then it's OK, but tuple is using parentheses, in order for Python to know that you are here to define a tuple of 1 elements, a= (1,): A=[x. >>> A=[1] >>> a [1] >>> a= (1) >>> A A it's a number, not a tuple. >>> a= (1,) >>> a (1,) >>> Second small detail: the invariant of a tuple refers to the tuple. Once each element is defined, "point" does not change. For example: >>> a [' A

. Usually the default name for this file is. bash_history. You can specify a new file name by assigning a value to the variable histfile.Cases$ echo $HISTFILE/home/lisa/.bash_history$ histfile= "/home/lisa/newhist"$ echo $HISTFILE/home/lisa/newhistThe above operation first displays the value of the variable histfile, then assigns it a new value of "/home/

Because Users group membership is defined in the different locations, it can be difficult to find out which groups exactly A user is a member of. A Convenient command to check that is groupmems . Use, for example, the command groupmems-g sales-l to see which users is a member of the group sales. This shows users who is a member of this group as a secondary group assignment, but also the users who is a member of this G Roup as the primary group assignment.[Email protected] ~]# Groupmems--helpusag

! Examples are described below. (1) Read lock on the actor table: Java code Mysql> lock table actor read; Query OK, 0 rows Affected (0.00 sec) (2) But access via aliases will prompt for errors: Java code Mysql> Select A.first_name,a.last_name,b.first_name,b.last_name from actor A,actor b where a.first_name = B.first_ Name and A.first_name = ' Lisa ' and a.last_name = ' Tom ' and a.last_name ERROR 1100 (HY000): Table ' A

Python deletes elements from listPaul's classmates had to turn away a few days ago, so how do we remove Paul from the existing list?If Paul's classmates were in the last one, we could delete them using the list pop() method :>>> L = [' Adam ', ' Lisa ', ' Bart ', ' Paul ']>>> L.pop () ' Paul ' >>> print l[' Adam ', ' Lisa ', ' Bart ']The pop () method always deletes the last element of the list , and it ret

1. Iteration 1.1 FeaturesIn Python, an iteration is done through a for ... in.Python's for loop can be used not only on a list or a tuple, but also on any other object that can iterateA For loop can work on an iterative object far more than List,tuple,str,unicode,dict, and if an object says it can iterate, then we iterate it directly with a for loop . The iterative operation is for a collection, regardless of whether the collection is ordered or unordered, we can always use the for loop to seque

strings: Copy Code code as follows: >>> map (str,[1,2,3,4,5]) [' 1 ', ' 2 ', ' 3 ', ' 4 ', ' 5 '] >>> Just one line of code, it's done. Let's look again at the exercises from the Gushe Python tutorial: Use the map () function to change the nonstandard English name entered by the user into the first letter capital and other lowercase canonical names. Input: [' Adam ', ' Lisa ', ' Bart '], output: [' Adam ', '

next element of the sequence cumulative calculation, the effect is: >>> from functools import reduce >>> def add (x, y): ... return x + y ... >>> reduce (add, [1, 3, 5, 7, 9]) Convert a string to an integer using map and reduce coordination From Functools import reduce def char2num: "Return {' 0": 0, ' 1 ': 1, ' 2 ': 2, ' 3 ': 3, ' 4 ': 4, ' 5 ': 5, ' 6 ': 6, ' 7 ': 7, ' 8 ': 8, ' 9 ': 9}[s] # Follow the key to take value def str2int (s): return reduce (lambda x, y:x * + y, ma

function once for each row of the external table. You can specify apply in the FROM clause of the query in the same way that you use the Join relational operator. Apply has two forms: CROSS apply and outer apply. Demonstrate: Use DemoGo CREATE TABLE Orders(The Customer VARCHAR (%) is not NULL,Product VARCHAR not NULL,Quantity INT not NULL)GoINSERT orders VALUES (' Mike ', ' Bike ', 3)INSERT orders VALUES (' Mike ', ' Chain ', 2)INSERT orders VALUES (' Mike ', ' Bike ', 5)INSERT orders VALUES ('

(int, s) # 数字列表变成int return reduce(numtoint, l)def numtoint(a, b): return 10 * a + bif __name__ == "__main__": print strtoint("356546") print isinstance(strtoint("356546"),int)>>> C:\pythonTest>python mapAndreduce.py>>> 356546>>> True10.2.1 Lambda functionCan be used to write single-line functions, so that when a simple logic processing need not write a function to deal with, directly with the lambda to handleThis can be said to simplify the above function:# str转换为int的函数def strtoi

numbers in this list into strings: Copy codeThe Code is as follows:>>> Map (str, [1, 2, 3, 4, 5])['1', '2', '3', '4', '5']>>> You only need a line of code. Let's take a look at the exercises from Gu Xuefeng's python Tutorial: Use the map () function to change the nonstandard English names entered by users into uppercase letters and other standard names in lower case. Input: ['Adam ', 'lisa', 'bart'], and output: ['Adam ', '

), (10, 3), (6, 5)]Print map (Lambda x:x * 3,[1,2,3,4,[3,2,1])Results: [3, 6, 9, 12, [3, 2, 1, 3, 2, 1, 3, 2, 1]] because [3,2,1] is a subsequence, multiplied by 3, the result consists of three groups [3,2,1]The use map() of functions, the user entered the non-standard English name, the first letter capitalized, other lowercase canonical name. Input: [‘adam‘, ‘LISA‘, ‘barT‘] , Output: [‘Adam‘, ‘Lisa‘, ‘Bart

example: 　　 $ HISTSIZE = 10 　　 Reset the value of HISTSIZE to 10. 　　 Historical events are saved in a file. the file name is specified by the HISTFILE variable. The default name of this file is. bash_history. You can assign a value to the variable HISTFILE to specify a new file name. 　　 [Example] 　　 $ Echo $ HISTFILE 　　 /Home/lisa/. bash_history 　　 $ HISTFILE = "/home/lisa/newhist" 　　 $ Echo $ HISTFILE