拆分包含“.”的字符串不使用内置函数

Question

I need to split the string and create a list of words without using inbuilt functions. Please help I'm missing something in the logic

st="i.like.this.very.much"
wordlist=[]
i=0
j=0
while i<len(st)-4:
    if st[i]==".":
        i+=1
    else:
        j=i
        word=""
        while st[j]!=".":
            word+=st[j]
            j+=1
            print(word)
        wordlist.append(word)
        i+=len(word)       
print(wordlist)

Output: C:\\Users\\Desktop>python raja1.py

i.like.this.very.much
i
l
li
lik
like
t
th
thi
this
v
ve
ver
very
['i', 'like', 'this', 'very']

Answer 1

Here's a quick-and-dirty solution that doesn't use len() or append() (and you can remove print() later):

st="i.like.this.very.much"
sp=[]
c=""
for s in st:
    if s == ".": 
        sp=sp+[c]
        c=""
    else: c+=s
if s != ".": sp=sp+[c]
print(sp)

The output is ['i', 'like', 'this', 'very', 'much'] .

Answer 2

Your only problem is that you've neglected to pick up the final word, because you stop 4 characters early for no apparent reason. Your loop only dumps the word if it ends with a period.

Run through the end of the string. Then simply add one more append after the loop -- but check that you do have a word to add, in case the input ended with a period:

if word:
    wordlist.append(word)

Also, you say that you can't use any built-ins, but your supposed solution uses len .