Python basis of logical problems (3)
1. Write a function that converts IP addresses to achieve an integer
4. The following requirements nums output
The following fragments required output
6. The results of written procedures: ------ my_dict
7. function result: --- add_end
9. The two queues implemented by a stack
10. Write about the results of the code and explain: parent
1. Write a function that converts IP addresses to achieve an integer
10.3.9.12 The conversion rule is: 10 00001010 . 3 00000011 . 9 00001001 12 is 00001100 or more spliced together and then calculates a decimal-binary results: 0,000,101,000,000,011 0,000,100,100,001,100 = ? ------------------ -------------------------------------------------- ------- DEF FUNC (IP): A = ip.split ( ' . ' ) S = '' L = [] for I in A: I = bin (int (I)) [2:] # bin (10) = 0b1010 I = i.rjust (. 8, ' 0 ' ) # 0000 the rjust 1010 (): returns a string right-aligned atoms, and filled with a new empty string 0, if the specified string length is less than the length of the original string is returned. l.append (I) S = s.join (L) return S RET = FUNC ( ' 10.3.9.12 ' ) Print (int (RET, 2 )) str.rjust (width [, FillChar]) -width - Specifies the total length of the specified character string after filling. -fillchar - padding characters, blank space by default. 10 octal binary Hexadecimal binary - bin (X, 8) bin (X, 10) bin (X, 16 ) 8-ary oct (x,2) - OCT (X, 10) OCT (X, 16 ) 10 hexadecimal int (X, 2) int (X,. 8) - int (X, 16 ) 16 hex hex (X, 2) hex (X, 8) hex (int (x, 10))
def num(): return [lambda x: i * x for i in range(4)] # 返回值是一个列表 print(num()) #[<function num.<locals>.<listcomp>.<lambda> at 0x00000000029726A8>, <function num.<locals>.<listcomp>.<lambda> at 0x0000000002972598>, <function num.<locals>.<listcomp>.<lambda> at 0x0000000002972730>, <function num.<locals>.<listcomp>.<lambda> at 0x00000000029727B8>] print([m(2) for m in num()]) #[6,6,6,6] def num(): return (lambda x: i * x for i in Range (. 4)) # return value is a generator Print (NUM ()) # <Generator Object NUM. <about locals>. <genexpr> AT 0x0000000002944B48> Print ([m (2) for m in NUM ()]) # [0, 2, 4, 6]
a =. 1 Print (ID (a)) DEF FUNC (a): a = 2 Print (ID (a)) # local variables and global variables addresses are not equal FUNC (a) Print (a) # . 1 for a variable function defines a = 2 after executing the function at this time to destroy the old printing is a global variable a a = [] DEF FUNC (a): a.append ( . 1 ) FUNC (a) Print (a ) # [1] for a list passed to a function of the increase of a value a is a constant address # variable data types and data type immutable
4. The following evaluation codes nums
num = range(2,20) for i in num: num =list(filter(lambda x:x==i or x%i ,num)) print(num) # 答案：[2, 3, 5, 7, 11, 13, 17, 19] num = range(2,20) for i in num: num =filter(lambda x:x==i or x%i ,num) print(num) print(list(num)) #<filter object at 0x000000000239C4E0> #[2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19]
5. Give the following output fragments
DEF say_hi (FUNC): DEF warpper (* args, ** kwargs): Print ( ' the HI ' ) --------------------------- --1 performed first RET = FUNC (* args, ** kwargs) Print ( ' the BYE ' ) ---------------------------- -4 executed after return RET return warpper DEF say_yo (FUNC): DEF warpper (* args, ** kwargs): Print ( ' YO2 ' ) ------------------- ---------- 2 calls, so before 4 return FUNC (* args, ** kwargs) return warpper @say_hi @say_yo DEF FUNC (): Print ( ' Rock & roll ' ) ----------------------- --------. 3 decorator, etc. 2 before been performed. 4 FUNC () results of the HI YO2 Rock & roll the BYE
6. Please write the output of the program
= {my_dict ' a ' : 0, ' B ' :. 1 }
DEF FUNC (D):
D [ ' a ' ] = ---------. 1 the value of a becomes. 1
return D
FUNC ( my_dict)
my_dict [ ' C ' ] = 2 ----- added a C
Print (my_dict)
{ ' a ' :. 1, ' B ' :. 1, ' C ' : 2} dictionary variable data type
DEF add_end (L = []): l.append ( " End " ) return L add_end () # nothing output add_end () # nothing output
''' data:{"time":"2016-08-05T13:13:05", "some_id":"ID1234", "grp1":{"fld1":1,"fld2":2}, "xxx2":{"fld3":0, "test":{‘fld5’:0.4}},"fld6":11,"fld7":7,"fld46":8 } fields:由"|"连接的以"fld"开头的字符串,如:fld2|fld3|fld7|fld19 def select(data,fields): return result ''' data = { "time":"1989-05-06", "some_id":123456, "grp1":{"fld1":1, "fld2":2}, "xxx2":{"fld3":0, "fld4":0.4}, "fld6":11, "fld7":7, "fld45":8 } def select(data, field): # "fld2|fld7|fld29" result = {} lst = field.split("|") for item in lst: result[item] = None for item in lst: # "fld2" if item in data: # result[item] = data[item] for value in data.values(): if type(value) == dict: d = select(value, field) for k, v in d.items(): if v: result[k] = v return result print(select(data, "fld2|fld7|fld29"))
9. The two queues implemented with a stack
Ideas: 1 . Any time there is always a two queues are empty. 2 . Additive element always to add an element to a non-empty queue. 3 . Remove the element when the element other team is always an outer end of the last element, introducing another empty queue, the last element of the team. Pseudocode: class StackWithTwoQueues (Object): DEF the __init__ (Self): self.q1 = [] self.q2 = [] DEF Push (Self, Item): self.q1.append (Item) DEF POP (Self): IF len (self.q1) == 0: return None the while len (self.q1) =. 1! : self.q2.append (self.q1.pop (0)) self.q1, self.q2 = self.q2,self.q1 return self.q2.pop(0)
10 Please give the correct answer
class the Parent (Object): X =. 1 class Child1 (the Parent): Pass class Child2 (the Parent): Pass Print (Parent.x, Child1.x, Child2.x) # 1,1,1 Child1.x = 2 Print ( Parent.x, Child1.x, Child2.x) # 1,2,1 Parent.x =. 3 Print (Parent.x, Child1.x, Child2.x) # 3,2,3 # value when the subclasses when not inherit the parent class, would like to inherit a super ()