访问findall retuned listt时出错

Question

嗨，我正在尝试使用find-all搜索模式，如果匹配，它将返回list。我正试图访问该列表，但出现了类似(IndexError：列表索引超出范围(的错误我写的片段如下。

return_from_findall = re.findall(regex, input)
if return_from_findall:
##trying to print the list element when list returned from finall is true##
print(return_from_finall[0])
## also trying to compare the list with another string like
if return_from_finall[0] == somestring:
print(match found)

两者都不工作

有人能帮助解决这个问题吗

我的程序：

import re
output = """
Another option is to use the name randomizer.
to randomize all the names on your list. 
In this case, you arent using it as a 
random name picker, but as a true name 
randomizer. For example, 
"""
match = 0
search_item = "Another option is to use the name randomizer"
expected_list = [
'Another option is to use the name randomizer.',
'to randomize all the names on your list.',
'In this case, you arent using it as a',
'random name picker, but as a true name',
'randomizer. For example,']

for line in output.splitlines():
line = line.strip()
print(" ################### ")
return_from_findall = re.findall(search_item, line)
print("searched line - ")
print(return_from_findall)
print("expected line - ")
print(expected_list[match])
if return_from_findall:
if return_from_findall[0] == expected_list[match]:
print("found match")

Answer 1

如果你想看看你有多少匹配，你可以使用以下方法：

import re
output = """
Another option is to use the name randomizer.
to randomize all the names on your list. 
In this case, you arent using it as a 
random name picker, but as a true name 
randomizer. For example, 
"""
match = 0
search_item = "Another option is to use the name randomizer"

for line in output.splitlines():
line = line.strip()

return_from_findall = re.findall(search_item, line)
if return_from_findall:
match += 1
print(f"Matches: {match}")

输出：

Matches: 1

Answer 2

如果您想比较expected_list中的行，看看它们是否出现在output字符串中，那么您可以执行以下操作：

output = """
Another option is to use the name randomizer.
to randomize all the names on your list. 
In this case, you arent using it as a 
random name picker, but as a true name 
randomizer. For example, 
"""
expected_list = [
'Another option is to use the name randomizer.',
'to randomize all the names on your list.',
'In this case, you arent using it as a',
'random name picker, but as a true name',
'randomizer. For example,']
for line in expected_list:
if line in output:
print("Found: ", line)
else:
print("Not found: ", line)

输出：

Found:  Another option is to use the name randomizer.
Found:  to randomize all the names on your list.
Found:  In this case, you arent using it as a
Found:  random name picker, but as a true name
Found:  randomizer. For example,