Quote escaping issues leads to lost backslash `\` and syntax errors

[darist]

Hi there, I ran into this situation:

Given yaml like:

arguments:
    - --textproto_content
    - 'query: "\''foo\'' = \"foo\"" x: "bar"'

Boundary layer produces Python code like (whitespace added for clarity):

arguments = [
          '--textproto_content',
          """query: "\'foo\' = \"foo\"" x: "bar"""",

There are two problems with the generated """query:... code above:

• The string ending with 4 " characters: """" causes a syntax error

  >>> print("""query: "\'foo\' = \"foo\"" x: "bar"""")
  File "<stdin>", line 1
  print("""query: "\'foo\' = \"foo\"" x: "bar"""")
                                                ^
  SyntaxError: unterminated string literal (detected at line 1)

• Even if I fix that syntax error, we lose the \ characters that were part of the original string (and we need so that the resulting string that is passed to the operator is valid textproto)

  >>> print("""query: "\'foo\' = \"foo\"" x: "bar" """)
  query: "'foo' = "foo"" x: "bar" 

Expected:

query: "\'foo\' = \"foo\"" x: "bar"