Python 오류 질문

def word_count(filename):
    f = open(filename)
    counts = {}
    for line in f :
        list = line.split()
        for word in list:
            if word in counts:
                conts[word] += 1
            else:
                counts = 1
    return counts
 
reply = 'y'
while reply == 'y':
    filename = input('파일 이름을 입력해 주세요: ')
    wc = word_count(filename)
 
    for word in sorted(wc):
        print(word, wc[word])
 
    reply = input('계속 하시겠습니까?:')

파일 이름을 입력해 주세요: you
Traceback (most recent call last):
  File "D:\KLDP\질문\파일속 단어갯수.py", line 18, in <module>
    wc = word_count(filename)
  File "D:\KLDP\질문\파일속 단어갯수.py", line 4, in word_count
    f = open(filename)
FileNotFoundError: [Errno 2] No such file or directory: 'you'

파일 이름을 입력해 주세요: you.txt
Traceback (most recent call last):
  File "D:\KLDP\질문\파일속 단어갯수.py", line 18, in <module>
    wc = word_count(filename)
  File "D:\KLDP\질문\파일속 단어갯수.py", line 9, in word_count
    if word in counts:
TypeError: argument of type 'int' is not iterable