Python为什么要在字符串中返回转义的反斜杠？

Question

'\"atg is a codon, isn\'t it?\" \"Yes, it is\", he answered'

gives as output:

'"atg is a codon, isn\'t it?" "Yes, it is", he answered'

Why is the escape character showing up in the output?

When I type the string below, this doesn't happen.

'This is a codon, isn\'t it?'

The output I get is this:

"This is a codon, isn't it?"

Answer 1

because in first one the whole string is in one-quote so another one-quotes should be escaped. Whereas in second one the whole string is in double quote.

>>> '\"atg is a codon, isn\'t it?\" \"Yes, it is\", he answered'
'"atg is a codon, isn\'t it?" "Yes, it is", he answered'
^                                                      ^
>>> 
>>> 'This is a codon, isn\'t it?'
"This is a codon, isn't it?"  # there is no need to escape the one-quote between double-quotes         
^                          ^

Answer 2

The escape character is needed because that is the string that, if typed out exactly, would reproduce the string. The string contains both single and double quotes, so whichever type encloses the string will need to be escaped within the string.

Answer 3

You get to choose either single quotes or double quotes to enclose a string. Any occurrences of your enclosing quote character must be escaped with a '\\'.

>>> b = 'Hello\'s'
>>> a = "Hello's"
>>> b = 'Hello\'s'
>>> c = 'Hello"s'
>>> d = "Hello\"s"
>>> a
"Hello's"
>>> b
"Hello's"
>>> c
'Hello"s'
>>> d
'Hello"s'
>>>