import re
'''
\w匹配包括下划线在内任何字母数字字符，它相当于类[a-zA-Z0-9]
\W匹配非任何字母数字字符包括下划线在内，它相当于类[^a-zA-Z0-9]
?P<>定义组里匹配内容的key(键)，<>里面写key名称，值就是匹配到的内容
'''
#
str1 = "123 is 456"
str2 = re.sub("\d+", "5555", str1)
print(str2)
inputStr = "hello crifan, nihao crifan";
replacedStr = re.sub(r"hello (\w+), nihao \1", "crifanli", inputStr);
print(replacedStr)
inputStr = "hello crifan, nihao crifan";
replacedStr = re.sub(r"hello (\w+), nihao \1", "\g<1>", inputStr);
print(replacedStr)
其中\g<1>表示组1
inputStr5 = "hello victor is a good man";
replacedStr5 = re.sub(r"(.+?)", "w", inputStr5);
print("vitor is :", replacedStr5)
if re.search("ob", inputStr5):
print("find it!")
if re.match("hello", inputStr5):
print("matched!")
def pythonReSubDemo():
"""
demo Pyton re.sub
"""
inputStr = "hello 123 world 456";
def _add111(matched):
intStr = matched.group("number"); #123
intValue = int(intStr);
addedValue = intValue + 111; #234
addedValueStr = str(addedValue);
return addedValueStr;
replacedStr = re.sub("(?P\d+)", _add111, inputStr);
print(replacedStr) #hello 234 world 567 pythonReSubDemo();
str3 = " **abc is abc*****"
str4 = " "
print(str4.strip())
if str4.strip():
print("not null")
else:
print("str4 is null")
print(str3)
print(str3.strip())