Python built-in function (-slice)

Official documents

class slice ( stop)

class slice ( start, stop[, step])

Return ASliceObject representing the set of indices specified by range(start, stop, step). The Startand StepArguments default to None. Slice objects has read-only data attributes start, stopand stepWhich merely return the argument values (or their default). They has no other explicit functionality; However they is used by numerical Python and all third party extensions. Slice objects was also generated when extended indexing syntax was used. For example: a[start:stop:step]Or a[start:stop, i]. See itertools.islice()For a alternate version that returns an iterator.

Description: 1. A function is actually a constructor for a slice class that returns a Slice object

2. The Slice object consists of 3 parameters, start, stop, step composition, start and step default is None. The slice object is primarily a slicing element on a Sequence object

>>>Help (Slice)|Return repr (self).| |Indices (...)| S.indices (len)(Start, stop, Stride)|      | Assuming a sequence of length Len, calculate the start andStop| Indices andThe stride length of the extended slice described by| S. Out of bounds indices is clippedincha manner consistent with the|handling of normal slices.|  | ---------------------------------------------------------------------- |Data descriptors defined here:| |Start| |Step| |Stop|  |  ---------------------------------------------------------------------- | Data andOther attributes defined here:| |__hash__= None

Li = [11,22,33,44,55,66,77]ret1= Li[none:5:none]#Start,stem to NoneRet2 = Li[:5:]#Ibid .Print(Ret1,ret2)#Output#[One, one, one, one, one, one, one, one, the other ]Ret3= Li[2:5:none]#step is NoneRet4 = Li[2:5:]Print(RET3,RET4)#Ibid .#Output#[From, to]#[From, to]Ret5= Li[1:6:3]Print(RET5)#Output#[A]

3.3 properties of the corresponding slice start, stop, and Step,slice functions also have 3 corresponding parameters start, stop, step, whose values are directly assigned to the slice object's start, stop, step

#Define C1C1 = Slice (5)Print(C1)#Output#Slice (None, 5, none)#Define C2C2 = Slice (2,5)Print(C2)#Output#Slice (2, 5, None)#define C3C3 = Slice (1,6,3)Print(C3)#Output#Slice (1, 6, 3)a= List (range (1,10)) Ret1= A[c1]#same as A[:5:]Print(RET1)#Output#[1, 2, 3, 4, 5]Ret2= A[c2]#same as A[2:5:]Print(Ret2)#Output#[3, 4, 5]Ret3= A[c3]#same as A[1:6:3]Print(RET3)#Output#[2, 5]

Python built-in function (-slice)