Your task is to make a program takes in a sentence (without puncuation), adds all words to a list and returns the sentence as a string which is the positions of the word in the list. Casing should not matter too.


Example
-----

`"Ask not what your COUNTRY can do for you ASK WHAT YOU CAN DO FOR YOUR country"`

becomes

`"01234567802856734"`

Another example
-----

`"the one bumble bee one bumble the bee"`

becomes

`"01231203"`

Difficulty: introductory

Starter code:

def compress(sentence):
	

Solutions:
def compress(sentence):
    ref = []
    for i in sentence.lower().split():
        if i not in ref:
            ref.append(i)
    return ''.join([str(ref.index(n)) for n in sentence.lower().split()])

def compress(sentence):
    memo = {}
    return ''.join(map(str, (memo.setdefault(s, len(memo)) for s in sentence.lower().split())))

def compress(sentence):
    l = sentence.lower().split()
    d = {}; ans = []
    for x in l:
        if not x in d: d[x] = len(d)
        ans += [str(d[x])]
    return ''.join(ans)


def compress(sentence):
    words = sentence.lower().split()
    uniq = sorted(set(words), key=words.index)
    return "".join(str(uniq.index(word)) for word in words)


def compress(sentence):
    ref = []
    for x in sentence.lower().split():
        if x not in ref:
            ref.append(x)
    return ''.join([str(ref.index(n)) for n in sentence.lower().split()])    

def compress(sentence):
    s = sentence.lower().split()
    sl = []
    for x in s:
        if x not in sl:
            sl.append(x)
    return ''.join(str(sl.index(x)) for x in s)


def compress(sentence):
    s = []
    for i in sentence.split():
        if i.lower() not in s:
            s.append(i.lower())
    return "".join([str(s.index(x.lower())) for x in sentence.split()])

def compress(sentence):
    t = []
    for i in sentence.lower().split(" "):
        if i.lower() not in t:
            t.append(i)
    return "".join([str(t.index(i.lower())) for i in sentence.split(" ")]) if sentence else "" 

def compress(sentence):
    l = sentence.lower().split()
    u = [s for i,s in enumerate(l) if l.index(s)==i]
    return ''.join(str(u.index(s)) for s in l)

def compress(s):
    d={}
    i=0
    r=''
    for w in s.lower().split():
        if w not in d:
            d[w]=i
            i+=1
        r+=str(d[w])
    return r