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...string-formatting) [2]str.format (https://docs.python.org/3/library/string.html#formatstrings) [3]string.Template documentation (https://docs.python.org/3/library/string.html#template-strings) [4]PEP 215: String Interpolation [5]PEP 292: Simpler String Substitutions [6]PEP 3101: Advanced String Formatting [7]PEP 498: Literal string formatting [8]FormattableString and C# native string interpolation (https://msdn.microsoft.com/en-us/library/dn961160.aspx) [9...
...Template and dict that allowed for a more complex placeholder syntax and a mapping that evaluated those placeholders. Internationalization The implementation supports internationalization by recording the original template string in the Template instance's template attribute. This attribute would serve as the lookup key in an gettext-based catalog. It is up to the application to turn the resulting string back into a Template for substitution. However, the Template class was designed to work ...
...string: LiteralString s: str = literal_string # OK literal_string: LiteralString = s # Error: Expected LiteralString, got str. literal_string: LiteralString = "hello" # OK Addition of literal strings: def expect_literal_string(s: LiteralString) -> None: ... expect_literal_string("foo" + "bar") # OK expect_literal_string(literal_string + "bar") # OK literal_string2: LiteralString expect_literal_string(literal_string + literal_string2) # OK plain_string: str expect_literal_string(li...
...string formatting techniques, so both systems can co-exist until it comes time to deprecate the older system. References [1]Python Library Reference - String formatting operations http://docs.python.org/library/stdtypes.html#string-formatting-operations [2]Python Library References - Template strings http://docs.python.org/library/string.html#string.Template [3][Python-3000] String formatting operations in python 3k https://mail.python.org/pipermail/python-3000/2006-April/000285.h...
...string from a list of 2-tuples Dictionary-related utility classes: NoKeyErrors (returns an empty string, never a KeyError), PartialStringSubstitution (returns the original key string, never a KeyError) New Modules This section lists details about entire new packages or modules that should be added to the Python standard library. fcgi.py : A new module adding support for the FastCGI protocol. Robin Dunn's code needs to be ported to Windows, though. Major Changes to Existing Modules This sec...
...string constants in Python. Currently, the value of string constant is all the text between quotations, maybe with escape sequences substituted, e.g.: def f(): """ la-la-la limona, banana """ def g(): return "This is \ string" print repr(f.__doc__) print repr(g()) prints: '\n\tla-la-la\n\tlimona, banana\n\t' 'This is \tstring' This PEP suggest two things: ignore the first character after opening quotation, if it is newline ignore in string constants all spaces and...
...string prefixes ('r' or 'u'). Such a string is processed for interpolation after the normal interpretation of backslash-escapes in its contents. The processing occurs just before the string is pushed onto the value stack, each time the string is pushed. In short, Python behaves exactly as if '$' were a unary operator applied to the string. The operation performed is as follows: The string is scanned from start to end for the '$' character (\x24 in 8-bit strings or \u0024 in Unicode strings)....
...String Interpolation, which proposed "formatted strings" was accepted September 9th, 2015. Additional background and rationale given during its design phase is detailed below. To recap that PEP, a string prefix was introduced that marks the string as a template to be rendered. These formatted strings may contain one or more expressions built on the existing syntax of str.format(). The formatted string expands at compile-time into a conventional string format operation, with the given expressions...
...strings to represent raw byte sequences will be more problematic. In addition, as Python's Unicode support has improved, it's easier to consider strings as ASCII-encoded Unicode objects. Proposed Implementation The number in parentheses indicates the Python version in which the feature will be introduced. Add a bytes builtin which is just a synonym for str. (2.5) Add a b"..." string literal which is equivalent to raw string literals, with the exception that values which conflict with the sou...
...strings. This change would make it easier to write code that works with either string type and would also make some existing code handle unicode strings. The C function PyObject_Str() would remain unchanged and the function PyString_New() would be added instead. Rationale Python has had a Unicode string type for some time now but use of it is not yet widespread. There is a large amount of Python code that assumes that string data is represented as str instances. The long-term plan for Pytho...
...string ending in newline, tab, etc. (but not when it ends in a space). Otherwise the softspace flag is set to one. The proposal changes this test slightly so that softspace is set to: -1 -- if the last object written is a string ending in a newline 0 -- if the last object written is a string ending in a whitespace character that's neither space nor newline 1 -- in all other cases (including the case when the last object written is an empty string or not a string) Then, the PRINT_NEWLINE opcod...
...Template PEP:12 Title:Sample reStructuredText PEP Template Author:David Goodger <goodger at python.org>, Barry Warsaw <barry at python.org>, Brett Cannon <brett at python.org> Status:Active Type:Process Created:05-Aug-2002 Post-History:30-Aug-2002 Contents Abstract Rationale How to Use This Template ReStructuredText PEP Formatting Requirements General Section Headings Paragraphs Inline Markup Block Quotes Literal Blocks Lists Tables Hyperlinks Internal and PEP...
...string literals would be in the source encoding at run-time, allowing then to output them to a file or render them to the user as-is. With Python 3, all strings will be Unicode strings, so the original encoding of the source will have no impact at run-time. Implementation The parser needs to be changed to accept bytes > 127 if no source encoding is specified; instead of giving an error, it needs to check that the bytes are well-formed UTF-8 (decoding is not necessary, as the parser converts...
...strings”, and the proposed one as “f-literals”. Furthermore, it will refer to the {}-delimited expressions in f-literals/f-strings as “expression portions” and the static string content around them as “string portions”. Motivation The current implementation of f-strings in CPython relies on the existing string parsing machinery and a post processing of its tokens. This results in several restrictions to the possible expressions usable within f-strings: It is impossible to use the quote chara...
...string]) (unkeyed hashes) new([key] , [string]) (keyed hashes) Create a new hashing object and return it. The first form is for hashes that are unkeyed, such as MD5 or SHA. For keyed hashes such as HMAC, key is a required parameter containing a string giving the key to use. In both cases, the optional string parameter, if supplied, will be immediately hashed into the object's starting state, as if obj.update(string) was called. After creating a hashing object, arbitrary string...
...string syntax [1]. The new syntax for strings, including the new bytes literal, is: stringliteral: [stringprefix] (shortstring | longstring) stringprefix: "b" | "r" | "br" | "B" | "R" | "BR" | "Br" | "bR" shortstring: "'" shortstringitem* "'" | '"' shortstringitem* '"' longstring: "'''" longstringitem* "'''" | '"""' longstringitem* '"""' shortstringitem: shortstringchar | escapeseq longstringitem: longstringchar | escapeseq shortstringchar: <any source character except "\" or newline or th...
...strings in such a way that allows recreation of the original byte string. Rationale The C char type is a data type that is commonly used to represent both character data and bytes. Certain POSIX interfaces are specified and widely understood as operating on character data, however, the system call interfaces make no assumption on the encoding of these data, and pass them on as-is. With Python 3, character strings use a Unicode-based internal representation, making it difficult to ignore the en...
...strings The usual boolean operators and and or can be used to combine expressions, and parentheses are supported for grouping. The pseudo-grammar is MARKER: EXPR [(and|or) EXPR]* EXPR: ("(" MARKER ")") | (STREXPR|VEREXPR) STREXPR: STRING [STRCMPOP STREXPR] STRCMPOP: ==|!=|in|not in VEREXPR: VERSION [VERCMPOP VEREXPR] VERCMPOP: (==|!=|<|>|<=|>=) SUBEXPR is either a Python string (such as 'win32') or one of the Strings marker variables listed below. VEREXPR is a PEP 440 version iden...
...string. This can lead to cases where the docstring and assignment may be separated by other expressions: class C: "C doc string" b = 2 def x(self): "C.x doc string" y = 3 return 1 "b's doc string" Since the definition of method "x" currently does not reset the used assignment name variable, it is still valid when the compiler reaches the docstring "b's doc string" and thus assigns the string to __doc_b__. A possible solution to this problem would be...
...string Format Goals Docstring Contents Docstring Basic Structure Unresolved Issues Rejected Suggestions Notice This PEP is rejected by the author. It has been superseded by PEP 287. Abstract Named Python objects, such as modules, classes and functions, have a string attribute called __doc__. If the first expression inside the definition is a literal string, that string is assigned to the __doc__ attribute. The __doc__ attribute is called a documentation string, or docstring. It is often us...