如果字符串以某个字符开头，如何在字符串中返回单词？ （蟒蛇）

Question

我正在构建一个用于练习的reddit机器人，将美元兑换成其他常用货币，并且我设法让转换部分工作正常，但现在我有点陷入困境将直接跟随美元符号的字符传递给转换器。

这就是我想要它的工作方式：

def run_bot():
    subreddit = r.get_subreddit("randomsubreddit")
    comments = subreddit.get_comments(limit=25)
    for comment in comments:
        comment_text = comment.body
        #If comment contains a string that starts with '$'
            # Pass the rest of the 'word' to a variable

例如，如果它正在审阅这样的评论：

  

＆＃34;我以5000美元的价格购买了一艘船并且很棒＃34;

它将分配＆＃39; 5000＆＃39;到一个变量，然后我将通过我的转换器

最好的方法是什么？

（希望有足够的信息，但如果人们感到困惑，我会添加更多信息）

Answer 1

您可以使用re.findall功能。

>>> import re
>>> re.findall(r'\$(\d+)', "I bought a boat for $5000 and it's awesome")
['5000']
>>> re.findall(r'\$(\d+(?:\.\d+)?)', "I bought two boats for $5000  $5000.45")
['5000', '5000.45']

OR

>>> s = "I bought a boat for $5000 and it's awesome"
>>> [i[1:] for i in s.split() if i.startswith('$')]
['5000']

Answer 2

如果您按照浮点数处理价格，可以使用：

import re

s = "I bought a boat for $5000 and it's awesome"

matches = re.findall("\$(\d*\.\d+|\d+)", s)
print(matches) # ['5000']

s2 = "I bought a boat for $5000.52 and it's awesome"
matches = re.findall("\$(\d*\.\d+|\d+)", s2)
print(matches) # ['5000.52']