Question

我有一个工作例程来确定新闻项目所属的类别。在Python中为标题，类别，子类别和搜索词指定值为RegExp时，该例程有效。

但是当从PostgreSQL中检索这些值作为字符串时，我不会得到任何错误，或者来自同一例程的结果。

我检查了数据类型，两者都是Python字符串。

可以采取哪些措施来解决这个问题？

# set the text to be analyzed
title = "next week there will be a presentation. The location will be aat"

# these could be the categories
category = "presentation"
subcategory = "scientific"

# these are the regular expressions
main_category_search_words = r'\bpresentation\b'
sub_category_search_words= r'\basm microbe\b | \basco\b | \baat\b'

category_final = ''
subcategory_final = ''

# identify main category
r = re.compile(main_category_search_words, flags=re.I | re.X)
result = r.findall(title)

if len(result) == 1:
    category_final = category

    # identify sub category
    r2 = re.compile(sub_category_search_words, flags=re.I | re.X)
    result2 = r2.findall(title)
    if len(result2) > 0:
        subcategory_final = subcategory

print("analysis result:", category_final, subcategory_final)

Answer 1

我非常确定您从PostgreSQL获得的内容不是raw string literal，因此您的RegEx无效。您必须在DB中明确地转义模式中的反斜杠。

print(r"\basm\b")
print("\basm\b")
print("\\basm\\b")

# output
\basm\b

as       # yes, including the line break above here
\basm\b

RegEx字符串在Python中直接分配时有效，但不能从PostgreSQL数据库中分配

1 个答案: