《笨办法学python》练习题中的程序，卡在这个错误上过不去了。

这是我根据书上打的，检查了好多遍没发现错误，求指教。万分感谢,加粗部分为错误。
第 28行 def convert(snippet, phrase):
^
SyntaxError: invalid syntax

import random
from urllib.request import urlopen
import sys
WORD_URL="http://learncodethehardway.org/words.txt"
WORDS=[]
PHRASES={
    "class %%%(%%%):":
    "Make a class named %%% that i _a %%%.",
    "class %%%(object):\n\t def __init__(self,***)":
        "class %%% has-a __init__ that takes self and *** params.",
    "class %%%(object):\n\t def *** (self,@@@)":
    "calss %%% has-a function *** that takes self and @@@ params.",
    "*** =%%%()":
    "Set *** to an instance of class %%%.",
    "***.***='***'":
    "From *** get the *** atrribute and set it to '***'."
}
 # do they want to drill phrases first
if len(sys.argv) ==2 and sys.argv[1]=="english":
    PHRASE_FIRST=True
else:
    PHRASE_FIRST=False
# load up the words from the website
#file=open(r'C:\Users\Basic ResearchCenter\Desktop\words.txt',encoding='utf-8')
#for word in file.readlines():
for word in urlopen(WORD_URL).readlines():
    WORDS.append(str(word.strip(),encoding='utf-8')    
**def convert(snippet,phrase):**
    class_names = [w.capitalize() for w in random.sample(WORDS,snippet.count("%%%"))]
    other_names =random.sample(WORDS,snippet.count("***"))
    results=[]
    param_names=[]
    
    for i in range(0,snippet.count("@@@")):
        param_count=random.randint(1,3)
        param_names.append(','.join(random.sample(WORDS,param_count)))    
    for sentence in snippet, phrase:
        result=sentence[:]
        for word in class_names:
            result=result.replace("%%%",word,1)
    for word in other_names:
        result=result.replace("***",word,1)
    for word in param_names:
        result=result.replace("@@@",word,1)
        results.append(result)
    return results
try:
    while True:
        snippets=list(PHRASES.keys())
        random.shuffle(snippets)
    
        for snippet in snippets:
            phrase=PHRASES[snippet]
            question, answer=convert(snippet,phrase)
            
            if PHRASE_FIRST:
                question, answer=answer,question
            print(question)
            input('>')
            print(f"ANSWER: {answer}\n\n")
except EOFError:
    print("\nBye")

WORDS.append(str(word.strip(),encoding='utf-8')

这行最后少了个)右括号

WORDS.append(str(word.strip(),encoding='utf-8'))

一般如果某一行报语法错误,可能是这一行或者前一行出问题了,检查的时候重点检查此行和上一行

27行右边少了个括号

第27行少了右括号

WORDS.append(str(word.strip(),encoding='utf-8'))