解析带有嵌套引号的字符串
解析带有嵌套引号的字符串
提问于 2019-03-15 01:04:51
我需要解析一个看起来像这样的字符串：
"prefix 'field1', '', 'field2', 'field3', 'select ... where (column1 = '2017') and ((('literal1', 'literal2', 'literal3', 'literal4', 'literal5', 'literal6', 'literal7') OVERLAPS column2 Or ('literal8') OVERLAPS column3 And (column4 > 0.0 Or column6 > 0.0)) And column7 IN_COMMUNITY [int1] And column5 = 'literal9') LIMIT 0 ', 'field5', 'field6', 'field7', 'field8', 'field9', '', 'field10'"我想得到一个类似下面的列表：
['field1', '', 'field2', 'field3', 'select ... where (column1 = '2017') and ((('literal1', 'literal2', 'literal3', 'literal4', 'literal5', 'literal6', 'literal7') OVERLAPS column2 Or ('literal8') OVERLAPS column3 And" (column4 > 0.0 Or column6 > 0.0)) And column7 IN_COMMUNITY [int1] And column5 = 'literal9') LIMIT 0 ', 'field5', 'field6', 'field7', 'field8', 'field9', '', 'field10']我尝试过使用正则表达式，但它在伪SQL语句的子字符串中不起作用。
我怎样才能得到那份名单呢？
回答 5
Stack Overflow用户
回答已采纳
发布于 2019-03-15 01:45:59
如果您知道SQL字符串应该是什么样子，那么这里有一种很脆弱的方法。
我们匹配SQL字符串，并将其余部分拆分为开始字符串和结束字符串。
然后我们匹配更简单的字段模式，并从开始为该模式构建一个列表，添加回SQL匹配，然后添加结束字符串中的字段。
sqlmatch = 'select .* LIMIT 0'
fieldmatch = "'(|\w+)'"
match = re.search(sqlmatch, mystring)
startstring = mystring[:match.start()]
sql = mystring[match.start():match.end()]
endstring = mystring[match.end():]
result = []
for found in re.findall(fieldmatch, startstring):
result.append(found)
result.append(sql)
for found in re.findall(fieldmatch, endstring):
result.append(found)则结果列表如下所示：
['field1',
'',
'field2',
'field3',
'select ... where (column1 = \'2017\') and (((\'literal1\', \'literal2\', \'literal3\', \'literal4\', \'literal5\', \'literal6\', \'literal7\') OVERLAPS column2 Or (\'literal8\')
OVERLAPS column3 And" (column4 > 0.0 Or column6 > 0.0)) And column7 IN_COMMUNITY [int1] And column5 = \'literal9\') LIMIT 0',
'field5',
'field6',
'field7',
'field8',
'field9',
'',
'field10']Stack Overflow用户
发布于 2019-03-15 03:10:59
由于字段的数量是固定的，并且非sql字段没有嵌入引号，因此有一个简单的三行解决方案：
prefix, other = string.partition(' ')[::2]
fields = other.strip('\'').split('\', \'')
fields[4:-7] = [''.join(fields[4:-7])]
print(fields)输出：
['field1', '', 'field2', 'field3', "select ... where (column1 = '2017') and ((('literal1literal2literal3literal4literal5literal6literal7') OVERLAPS column2 Or ('literal8') OVERLAPS column3 And (column4 > 0.0 Or column6 > 0.0)) And column7 IN_COMMUNITY [int1] And column5 = 'literal9') LIMIT 0 ", 'field5', 'field6', 'field7', 'field8', 'field9', '', 'field10']Stack Overflow用户
发布于 2019-03-15 01:09:25
有人指出你的字符串格式不正确，我用了这个：
mystr = "prefix 'field1', '', 'field2', 'field3', 'select ... where (column1 = '2017') and ((('literal1', 'literal2', 'literal3', 'literal4', 'literal5', 'literal6', 'literal7') OVERLAPS column2 Or ('literal8') OVERLAPS column3 And" (column4 > 0.0 Or column6 > 0.0)) And column7 IN_COMMUNITY [int1] And column5 = 'literal9') LIMIT 0 ', 'field5', 'field6', 'field7', 'field8', 'field9', '', 'field10'"
found = [a.replace("'", '').replace(',', '') for a in mystr.split(' ') if "'" in a]它返回：
['field1',
'',
'field2',
'field3',
'select',
'2017)',
'(((literal1',
'literal2',
'literal3',
'literal4',
'literal5',
'literal6',
'literal7)',
'(literal8)',
'literal9)',
'',
'field5',
'field6',
'field7',
'field8',
'field9',
'',
'field10']页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/55168323
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