如何在python2.7中的字符串中嵌入字符串，其中有转义引号？

string1 = 'I\'m embedding a string within a string.'
print(string1)

I'm embedding a string within a string.

string2 = "I'm embedding a \"quoted\" string within a string."
print(string2)

I'm embedding a "quoted" string within a string.

string3 = r'I\'m embedding a string within a string.'
print(string3)

I\'m embedding a string within a string.