nested while loops python

=SYS.ARGV[1] # #相当于shell中的 The first parameter of the script commandFILE2=SYS.ARGV[2] # #相当于shell中的 The second argument of the $ $ script commandX=open (File1)Y=open (File2, ' W ')For I in x:Y.writelines (i)Y.close ()X.close ()################################Module (/usr/lib64/python2.7/)Import Module Name # #导入模块中所有函数Module name. function () # #调用函数The name of the function. VariableFrom Module name Import function # # #只导入模块中的一个函数From NB Import StarImport module, module, module # # #导入多个模块逗号隔开

ConditionsSimilar to other languages, Python uses if...elif...else to form branches, supporting three-mesh operators? : There is no switch in Python, but the indentation feature makes the IF...ELIF...ELSE structure as easy to readLoop controlIn Python, in addition to the Break,continue two general loop control statements, there is a pass that performs an empty op

statement is: If If statement execution has a feature, it is judged from the top down, if in a certain judgment is true, the statement corresponding to the sentence after the execution, ignore the remaining elif and else, so please test and explain why the following program prints the teenager: Age = >= 6: print ' teenager ' elif age >=: print ' adult ' else: print ' Kid If judgment conditions can also be abbreviated, such as writing: If x: print ' T

classes.Del:del keyword Delete is two things, one is the object's reference , and the other is the name of the variable, Del is not deleted value , in Python is There is no way to delete the value, and the Python interpreter is responsible for the memory collection.The. EXEC: the keyword exec executes the python code stored in the string and can provide the nam

the programSummaryThe colon after the IF statementThe affiliation is represented by the indentation of four spaces and cannot be indented in PythonIf StatementElif StatementElif StatementElseStatementFor loopFor a in [3,4.4, ' life ']: print aFor a in range: print a**2//* * means powerWhile loopWhile I Break the LoopFor I in range (10): Continue Print IFor I in range: if i = = 2: Break Print IFunctionFirst, we'll define a function to illustrate the function.Def square_

=[1,2,3]>>> x==yDisplay: True>>> x==zDisplay: True>>> x is yDisplay: True>>> X is ZDisplay: False3, in, membership operator>>> if ' s ' in Name:>>> print (' Your name contains the letter "s")>>> Else:>>> print (' Your name does not contain ' s '. ')4. Assert, Assert>>>age=-1>>> assert 0Showing: assertionerror:the must be realistic5. While loop>>> x=1>>> while x>>> Print (x)>>> x+=16. For loop>>> numbers=[0,1,2,3,4,5,6,7]>>> for number in numbers:>>> Print (number)

Print the 9-9 multiplication table using Python loops (including while for) and pythonwhile I. Print the 9-9 multiplication table in a for Loop # Note: Due to the poor control of indentation in the browser, please forgive me. images will be imported later. 1.1 lower left corner For I in range (1, 10 ): For j in range (1, I + 1 ): Print ('% d * % d = % 2d \ t' % (j, I, I * j), end = '')Print () : 1.2 bott

In a single-layer loop exit, use break to exit, so what is the multi-layer loop? Witty people use the flag identifier in the way, for example:a=['a', 1,2,3,4]b=['b', 1,2,3,4]c=['C', 1,2,3,4]d=['D', 1,2,3,4]break_flag=0 whilebreak_flag==0:y_n=input ('A,yes or No:') ifY_n = ='N': Break elifY_n = ='y': forIinchA:Print(i) whileBreak_flag = =0:y_n_2=input ('B,yes or No:') ify_n_2=='N': Print('Exit') Break_flag=1elify_n_2=='y': forIinchB:

While and for loopsGeneral formatWhile ElseThe Else section is optional and is executed if control leaves the Wihle and there is no break.Break: Jump out of the nearest loopContinue: Jumps to the beginning of the nearest loopPass: Nothing is done, just a placeholderelse: It will only execute if it encounters a breakFor loopGeneral formatFor ElseThe For loop also supports an else part that also encounters a break to executeBasic applicationsFor x in [' Spam ', ' eggs ', ' ham ']:print (x);sum = 0

If Loop: two optionsExample 1:1 a=2if a:3 print ('the Number less than')4Else:5 Print ( ' Thank you! ')Example 2:While loop: Repeats a function multiple timesExample 11 greetings=12 while greetings3: #这里记住了是 3 print ('hello! '*greetings)4 greetings=greetings+12 . Pyhello! Hello!hello! Hello!hello!hello!Example 2 For loop: Iterate through every element in the listExample 1 1 names=[ " a ", " b ", " c 2 for name in names: 3 Print ( hello! +name) 1 . Pyhello! Ahel