str1 = "This is a 'test'"print(str1)str1 = 'This is a "test"'print(str1)str1 = "This is a \"test\""print(str1)str1 = 'This is a \'test\' 'print(str1)str1 = "This is a single \string"print(str1)'''len()lower()upper()str()'''print(len("abc"))print("aAbc".lower())print("abc".upper())print("abc" +  str(2))print("hello" + " " + "world")

result:

C:\Users\FeiLiu\AppData\Local\Programs\Python\Python36\python.exe C:/Users/FeiLiu/PycharmProjects/GetBluePageInfo/src/stringTest.pyThis is a 'test'This is a "test"This is a "test"This is a 'test' This is a single string3aabcABCabc2hello world