读取文本直到匹配字符串并将其打印为单行

Question

我正在尝试以 python 初学者的身份编写程序。 此函数扫描给定的文本。每当我遇到符号“@、&、% 或 $”时，我必须将文本提取到该点并将其打印为单行。另外，我必须跳过符号，从符号后面的字母开始下一行并打印它，直到遇到另一个符号。 我希望我说得好。

symbols= "@, &, %, $”"
for symbol in text:
     if text.startswith (symbols):
        print (text)

我知道这不正确，但我只能这么想。任何帮助表示赞赏。

Answer 1

IIUC，你需要用每个分隔符来分割字符串，所以你可以这样做：

symbols = "@, &, %, $".split(', ')
print(symbols)  # this is a list

text = "The first @ The second & and here you have % and finally $"

# make a copy of text
replaced = text[:]

# unify delimiters
for symbol in symbols:
    replaced = replaced.replace(symbol, '@')

print(replaced)  # now the string only have @ in the place of other symbols

for chunk in replaced.split('@'):
    if chunk:  # avoid printing empty strings
        print(chunk)

输出

['@', '&', '%', '$']  # print(symbols)
The first @ The second @ and here you have @ and finally @  # print(replaced)
The first 
 The second 
 and here you have 
 and finally 

第一步：

symbols = "@, &, %, $".split(', ')
print(symbols)  # this is a list

将您的字符串转换为列表。第二步使用replace 替换所有符号，因为str.split 仅适用于单个字符串：

# unify delimiters
for symbol in symbols:
    replaced = replaced.replace(symbol, '@') 

第三步也是最后一步是按所选符号（即@）分割字符串：

for chunk in replaced.split('@'):
    if chunk:  # avoid printing empty strings
        print(chunk)

Answer 2

如果我按照字面上给您的说明进行操作，我相信它不会比将文本中的这 4 个特殊字符中的每一个都替换为换行符更好：

text = """This is a line with @ and & in it.
This line has % and $ in it.
This line has nothing intersting in it.
This line has just @ in it.
The end.
"""
text = text.replace('@', '\n').replace('&', '\n').replace('%', '\n').replace('$', '\n')
print(text)

打印：

This is a line with 
 and 
 in it.
This line has 
 and 
 in it.
This line has nothing intersting in it.
This line has just 
 in it.