python 实现字符串的切片功能

'''string切片'''
def string_split(stringone,split):
    m = []
    if  type(split)!=str:
        return  False
    if split not in stringone :
        m.append(stringone)
        return m
    if type(stringone)!=str:
        return False
    if not  split:
        m.append(stringone)
        return m
    else:
        h=0
        l=0
        for i in range(len(stringone)):
            if stringone[i]==split:
                if i==0 and h==0:
                    n = (stringone[0])
                elif h>0:
                    n=stringone[l:i]
                else:
                    n=stringone[0:i]
                if i==len(stringone)-1:
                    c = stringone[len(stringone)-1]
                elif h>0 :
                    c=stringone[-1]
                else:
                    c=''
                if len(n)!=0 :
                    m.append(n)
                if len(c)!=0:
                        m.append(c)
                i += 1
                h += 1
                l= i
            else:
                i+=1
        return m
print(string_split('12,22,11',split='1,'))