编写正则表达式时,可以跨多行编写表达式并包含注释,然后使用re.VERBOSE
传递编译版本之前的选项。我想做类似的事情pandas.read_sql_query
.
例如,代替:
result = pd.read_sql_query('select a.gvkey, a.tic, a.datadate as fyearend, year(a.datadate) as year, month(a.datadate) as fyrc, b.datadate, month(b.datadate) as month, b.trt1m from COMPM.FUNDA a join COMPM.SECM b on a.gvkey = b.gvkey and year(a.datadate) = year(b.datadate) where a.TIC = "IBM" and a.datafmt = "STD" and a.consol="C" and a.indfmt = "INDL" and year(a.datadate)>1980', engine)
我想写一些类似的东西:
q = """select a.gvkey,
a.tic, #COMMENTS
a.datadate as fyearend, #COMMENTS
year(a.datadate) as year, #COMMENTS
month(a.datadate) as fyrc, b.datadate,
month(b.datadate) as month,
b.trt1m
from COMPM.FUNDA a join COMPM.SECM b on a.gvkey = b.gvkey and year(a.datadate) = year(b.datadate)
where a.TIC = "IBM"
and a.datafmt = "STD"
and a.consol="C"
and a.indfmt = "INDL"
and year(a.datadate)>1980
"""
result = p.read_sql_query(q ,engine)
我的问题与this https://stackoverflow.com/questions/33944522/is-it-possible-to-split-a-sequence-of-pandas-commands-across-multiple-lines关于将 python 命令拆分为多行的问题,但我想在查询中添加注释。
正如我所提到的,我想要在 pandas/SQL 情况下执行的操作类似于在正则表达式情况下执行的操作re.VERBOSE
。这是正则表达式的示例:
pattern = r'''\s(shares?| #COMMENTS
warrants?| #COMMENTS
stock| #AND SO ON...
(non)?vest(ed)?
)\b
'''
crit = re.compile(pattern_nopt, re.VERBOSE)
match=re.search(crit, string)
这将使查询更具可读性,并且我发现在与共同作者共享代码时详尽地注释查询很重要。