题解 | #修正错误的字母#

a=input()
b=a.replace('a*','ab')
print(b)
# Python replace() 方法把字符串中的 old（旧字符串） 替换成 new(新字符串)，如果指定第三个参数max，则替换不超过 max 次。

str = "this is string example....wow!!! this is really string";
print str.replace("is", "was");
print str.replace("is", "was", 3);
#输出：thwas was string example....wow!!! thwas was really string
      thwas was string example....wow!!! thwas is really string