f”…” strings are great when interpolating expression results into a literal, but you don’t have a literal, you have a template string in a separate variable. You can use str.format() to apply values to that template: name=[“deep”,”mahesh”,”nirbhay”] user_input = “certi_{element}” # this string i ask from user for value in name: print(user_input.format(element=value)) String formatting placeholders … Read more
You can’t. Backslashes cannot appear inside the curly braces {}; doing so results in a SyntaxError: >>> f'{\}’ SyntaxError: f-string expression part cannot include a backslash This is specified in the PEP for f-strings: Backslashes may not appear inside the expression portions of f-strings, […] One option is assinging ‘\n’ to a name and then … Read more
I don’t think formatted string literals allowing nesting (by nesting, I take it to mean f'{f”..”}’) is a result of careful consideration of possible use cases, I’m more convinced it’s just allowed in order for them to conform with their specification. The specification states that they support full Python expressions* inside brackets. It’s also stated … Read more
An f-string is syntax, not an object type. You can’t convert an arbitrary string to that syntax, the syntax creates a string object, not the other way around. I’m assuming you want to use user_input as a template, so just use the str.format() method on the user_input object: variable = 42 user_input = “The answer … Read more
f-strings are code. Not just in the safe, “of course a string literal is code” way, but in the dangerous, arbitrary-code-execution way. This is a valid f-string: f”{__import__(‘os’).system(‘install ransomware or something’)}” and it will execute arbitrary shell commands when evaluated. You’re asking how to take a string loaded from a text file and evaluate it … Read more
From Style Guide for Python Code: The preferred way of wrapping long lines is by using Python’s implied line continuation inside parentheses, brackets and braces. Given this, the following would solve your problem in a PEP-8 compliant way. return ( f'{self.date} – {self.time}\n’ f’Tags: {self.tags}\n’ f’Text: {self.text}’ ) Python strings will automatically concatenate when not … Read more
See PEP 498 Literal String Interpolation: The expressions that are extracted from the string are evaluated in the context where the f-string appeared. This means the expression has full access to local and global variables. Any valid Python expression can be used, including function and method calls. So the expressions are evaluated as if they … Read more
Although there is a custom syntax error from the parser, the same trick works as for calling .format on regular strings. Use double curlies: >>> foo = ‘test’ >>> f'{foo} {{bar}}’ ‘test {bar}’ It’s mentioned in the spec here and the docs here.
I’m afraid that it will be deprecated during the next Python versions Don’t be, str.format does not appear (nor has a reason) to be leaving any time soon, the PEP that introduced fprefixed-strings even states in its Abstract: This PEP does not propose to remove or deprecate any of the existing string formatting mechanisms. Formatted … Read more
I think you have an old version of python. try upgrading to the latest version of python. F-string literals have been added to python since python 3.6. you can check more about it here