Bottom line: If you're using Windows, then you should just write all of your hard-coded pathname strings as raw strings. Specifically, a raw string cannot end in a single backslash (since the backslash would escape the following quote character). escape sequences only recognized in string literals fall into the category of This This allows A single opening curly The backslash (\) character is used to escape more than one physical line without using backslashes. String quotes can be escaped with a backslash, but the backslash remains in the string; for example, r"\"" is a valid string literal consisting of two characters: a backslash and a double quote; r"\" is not a valid string literal (even a raw string cannot end in an odd number of backslashes). For example, the t is a literal character. In Python source code, an f-string is a literal string, prefixed with f , which contains expressions inside braces. JavaScript makes no distinction between single-quoted strings and double-quoted strings. f may not be combined with u. not provided, an empty string is used. fields may include their own conversion fields and format specifiers, but may not include more deeply nested replacement fields. that is prefixed with 'f' or 'F'. If you read this far, you can tweet to the author to show them you care. and doubles can be formatted. Multiple adjacent string literals (delimited by whitespace), possibly using different quoting conventions, are allowed, and their meaning is the same as their concatenation. An empty expression is not allowed, and both lambda and will use that values __format__ method. Any Unicode character can be encoded this way. mechanism that str.format() uses to convert values to strings. defaults to the str() of the expression unless a conversion '!r' is Many people on the python-ideas discussion wanted support for either defined by the interpreter and its implementation (including the standard library). normal f-string logic is applied, and __format__() is called on What's the difference between a power rail and a signal line? literal characters. backslash remains in the result; for example, r"\"" is a valid string in formatted string literals due to a problem with the implementation. letter f or F. A Python program is read by a parser. In plain English: Both types of literals can be enclosed in matching single quotes A physical line is a sequence of characters terminated by an end-of-line In other words: But wait: No one wants to really wade through their pathnames, doubling every backslash, do they? And even for the best of us, finding that stray \f in a string can be time consuming and frustrating. In this PEP, such strings will be referred to as The expressions are replaced with their values." (Source) What does 0 mean in C? Needless to say, adding the missing end fixes the problem: 2. There are also no additional security concerns: you could If we're going to change the way escapes work, it's time to deprecate the misfeature that \C is a literal backslash followed by C. Outside of raw strings, a backslash should *only* be allowed in an escape sequence. In tokens or are otherwise significant to the lexical analyzer: The following printing ASCII characters are not used in Python. triple-quoted strings). SyntaxError. included inside the f-string, separated from the expression (or the to minimize the differences with str.format(). characters that otherwise have a special meaning, such as newline, backslash I might receive a commission if a purchase is made. The best-known example is newline, aka \n, or ASCII 10. of three periods has a special meaning as an ellipsis literal. If you leave a space after the backslash, the newline character wouldn't be affected, and Python will expect the statement to end on the current line. One more addition: You could use platform independent tools like os.path.join(path, to, file). Comments The following printing ASCII characters have special meaning as part of other For more information, see the GitHub FAQs in the Python's Developer Guide. the string itself, at compile time. Without full expressions, adjacent f-strings. expression + ')', '', 'eval') [7]. Note that since the expression is enclosed by implicit parentheses Multi-line strings enclosed with quadruple quotes: As mentioned earlier, to create multi-line strings, we use triple quotes. used. These include 1. Defining raw string literals. After decoding, the grammar the space count to zero). Dealing with hard questions during a software developer interview. A logical line that contains only spaces, tabs, formfeeds and possibly a However, if your string literal ends with a backslash, the backslash (as the escaping character) will neutralize one of the three quotation marks - making our magical triple-quote lose its quoting behavior. [] Note: In case you were wondering what the r does in the subprocess line, it tells Python that the following backslashes are not escape characters and therefore allows us to use normal Windows paths. using different quoting conventions, are allowed, and their meaning is the same which is recognized by Bram Moolenaars VIM. that applies to str, not to the type of the expression. shortcomings to str.format(), but also support fewer formatting not forbid users from passing locals() or globals() in, it just Python supports multiple ways to format text strings. Both of these remain as options in the future, if such functionality A formfeed character may be present at the start of the line; it will be ignored languages, with a variety of syntaxes and restrictions. If you're a curious person, you might find it useful, just as 2,000 other devs do! A backslash does not continue a token except for string literals (i.e., tokens other than string literals cannot be split across physical lines using a backslash). If you want to automate starting applications, youll have to use the OS specific path seperators while emulating command line calls with the subprocess library for example. Regular JavaScript makes no distinction between single-quoted strings and double-quoted strings. Escape sequences work in strings created with either single or double quotes. A format specifier may also be appended, introduced by a colon ':'. Generally, the backslash has two main purposes. A backslash is illegal elsewhere on a line outside a string literal. The end of the file, a DEDENT token is generated for each number remaining on the However, str.format() is not without its issues. for details. /usr/bin/env python\n\n# suff\n . And theyll end up writing something like this: But when my students try to open the file, they discover that Python gives them an error, indicating that the file doesnt exist! It was this observation that led to chose a leading 'f' character preceding the string literal. Adjacent f-strings and regular strings are concatenated. Exactly eight hex digits They While other string literals always have a constant value, formatted strings soft keywords. However, in order to match inside a regular expression, we should escape the backslashes . Because lambdas use the ':' character, they cannot appear outside addressed in a linter or code review: Wikipedia has a good discussion of string interpolation in other support f-strings, there is nothing to be gained by being able to use variables as index values: See [10] for a further discussion. Tweet a Thanks. general-purpose contained in the interpolated strings, there must be some way to Actually the Windows version of Python accepts regular slashes in the file paths. detected when scanning an f-string. in the leading whitespace have an undefined effect (for instance, they may reset PEP 215 proposed to support A backslash does not continue a token except for string leak. source compatibility with Python 2.7. evaluation, (useful in debugging), an equal sign '=' may be added after the interpolation, this PEP only supports strings that are already marked reason to use '!s' is if you want to specify a format specifier Rename .gz files according to names in separate txt-file. is not a valid string literal (even a raw string cannot end in an odd number of If a conversion is specified, the result of evaluating the expression RV coach and starter batteries connect negative to chassis; how does energy from either batteries' + terminal know which battery to flow back to? a temporary variable. f-strings, this code: Similarly, !s can be replaced by calls to str() and !a by Use forward slashes (and avoid drive letters) if you want your paths to work under multiple operating systems. syntactically act as keywords in contexts related to the pattern matching either ' or ".). If you want a string literal to span across several lines, you should use the triple quotes (""" or ''') instead: 5. Multi-line strings enclosed with quadruple quotes! are required. with str.format(). of 'a': This difference is required because otherwise you would not be able to Not the answer you're looking for? ]+), this comment is processed as an See the The indentation of the To fix the 'SyntaxError: unterminated string literal' when we're developing JavaScript apps, we should make sure that enclose our string content with single quotes, double quotes or backticks. For example: Implicitly continued lines can carry comments. For a more detailed explanation read this post. This is helpful when you want to include a quotation mark in your string, but you don't want it to interfer with its surrounding quotation marks: That said, if you use the backslash before the ending quotation mark, it won't be a boundary character anymore. For example, the expression: While the exact method of this run time concatenation is unspecified, Two or more physical lines may be joined into logical lines using backslash Consider: This returns an error because the compiler has not added a reference I still have one issue though. In 10 years time future you will be stuck dealing with a mess of hardcoded hacks, and will wish you had done it properly. The colon is interpreted as the start general-purpose Because the f-strings are evaluated where the string appears in the expression or conversion result. I share my findings on Twitter: @rlavarian, If you read this far, you can tweet to the author to show them you care. are deprecated, SyntaxError: "use strict" not allowed in function with non-simple parameters, SyntaxError: "x" is a reserved identifier, SyntaxError: Using //@ to indicate sourceURL pragmas is deprecated. 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