我想在Python中编写一个正则表达式来匹配具有两个以上参数的函数,以便以下表达式匹配:
function(1, 2, 3)
function(1, 2, 3, 4)
function(1, function(1, 2), 3)
function(function(function(1, 2), 2), 2, 3, 4)
但以下情况则不然:
function(1, 2)
function(1, function(1, function(1, 2)))
function(1, function(function(1), 2))
我最好的尝试是以下表达式,它仅适用于没有嵌套函数的情况:
\w+\((?:.*,){2,}.*\)
我应该用什么表达方式来代替?
为了好玩,您可以递归删除内部函数并计算剩余参数:
import re
#https://peps.python.org/pep-0008/#function-and-variable-names
pyfunc = r"\b[a-zA-Z_][a-zA-Z0-9_]*"
pat = fr"({pyfunc}\(.*)(?:{pyfunc})?({pyfunc}\(.+?\))(.+)"
def fn(s):
if len(re.findall(pyfunc, s)) > 1:
new_s = re.sub(pat, r"\1-\3", s)
return fn(new_s)
else:
return s
正则表达式:[演示]
输出:
# `text` is the multistring holding your expressions
for exp in text.splitlines():
if (n:=fn(exp).count(",")) > 1:
print(f"{exp:<50}", n, f"{'MATCH':>10}")
else:
print(f"{exp:<50}", n, f"{'NO-MATCH':>10}")
function(1, 2, 3) 2 MATCH
function(1, 2, 3, 4) 3 MATCH
function(1, function(1, 2), 3) 2 MATCH
function(function(function(1, 2), 2), 2, 3, 4) 3 MATCH
function(1, 2) 1 NO-MATCH
function(1, function(1, function(1, 2))) 1 NO-MATCH
function(1, function(function(1), 2)) 1 NO-MATCH