Python detects whether a character in a character set is included in a string

Purpose

Detects if a character in a character set is contained in a string

Method

The simplest method is as follows, clear, universal, fast, suitable for any sequence and container

Copy the Code code as follows:

def containany (Seq,aset):
For C in SEQ:
If C in Aset:
Return True
Return False

The second applies to the Itertools module to improve a bit of performance, essentially the same way as the former (although this approach violates Python's core point of view: concise, clear)

Description of Itertools.ifilter (predicate, iterable)

Make a iterator that filters elements from iterable returning only those for which the predicate is True. IF predicate is None, return the items ' is true.

For example:

IFilter (Lambda x:x%2, Range)--1 3 5 7 9

Copy the Code code as follows:

Import Itertools

def containany (Seq,aset):

For item in Itertools.ifilter (ASET.__CONTAIN__,SEQ):

Return True

Return False

If you want to detect whether two strings are inclusive, you must check all subkeys at this point, preferably the set type, where set (Aset). Difference (seq) is an element that exists in aset and that SEQ does not:
Copy the Code code as follows:

def containall (Seq,aset):
Return not set (Aset). difference (seq)

For example, the following example:

Copy the Code code as follows:

In [4]: l1=[1,2,3,4]

In [5]: l2=[1,4,3,1]

In [6]: Containall (L1,L2)
OUT[6]: True

In [7]: Containall (L2,L1)
OUT[7]: False

Note that set.symmetric_difference refers to two unique elements of a collection
Copy the Code code as follows:

In [9]: l2=[3,2,4,5]
In [ten]: X=set (L1)
In [All]: X.symmetric_difference (L2)
OUT[11]: Set ([1, 5])

