string-formatting

Python Version 3.5 I'm trying to make an API call to configure a device using json as the format. Some of the json will vary depending on the desired naming, so I need to call a variable in the string. I am able to accomplish this using the old style %s... % (variable) , but not with the new style {}... .format(variable) . Failed EX: (Testing with {"fvAp":{"attributes":{"name":(variable)}}}) a = "\"app-name\"" app_config = ''' { "fvAp": { "attributes": { "name": {} }, "children": [ { "fvAEPg": { "attributes": { "name": "app" }, "children": [ { "fvRsBd": { "attributes": { "tnFvBDName": "default

This question already has answers here : Formatting decimal places with unknown number (4 answers) This in Swift (1.2) let doubleValue1 = Double(10.116983123) println(String(format: "%.2f", doubleValue1)) let doubleValue2 = Double(10.0) println(String(format: "%.2f", doubleValue2)) Prints 10.12 10.00 I'm looking for a way using a formatter or a direct string format and not via string manipulation, to remove the trailing zeroes, so to print: 10.12 10 The closest I got is: let doubleValue3 = Double(10.0) println(String(format: "%.4g", doubleValue3)) But g uses significant digits, which means I

In Java, how can you determine if a String matches a format string (ie: song%03d.mp3 )? In other words, how would you implement the following function? /** * @return true if formatted equals String.format(format, something), false otherwise. **/ boolean matches(String formatted, String format); Examples: matches("hello world!", "hello %s!"); // true matches("song001.mp3", "song%03d.mp3"); // true matches("potato", "song%03d.mp3"); // false Maybe there's a way to convert a format string into a regex? Clarification The format String is a parameter. I don't know it in advance. song%03d.mp3 is

I've heard that using StringBuilder is faster than using string concatenation, but I'm tired of wrestling with StringBuilder objects all of the time. I was recently exposed to the SLF4J logging library and I love the "just do the right thing" simplicity of its formatting when compared with String.format. Is there a library out there that would allow me to write something like: int myInteger = 42; MyObject myObject = new MyObject(); // Overrides toString() String result = CoolFormatingLibrary.format("Simple way to format {} and {}", myInteger, myObject); Also, is there any reason (including

I have a Python object with attributes a , b , c . I still use old string formatting, so I'd normally print these manually: print 'My object has strings a=%s, b=%s, c=%s' % (obj.a, obj.b, obj.c) Lately, my strings have been getting super long, and I'd much rather be able to simply pass the object into a string format function, something like: print 'My object has strings a=%a, b=%b, c=%c'.format(obj) However, the syntax is incorrect. Is this possible? You can use the .attribute_name notation inside the format fields themselves: print 'My object has strings a={0.a}, b={0.b}, c={0.c}'.format(obj

I have just taken over some code and I see this used a lot. It seems to take the integer and create a string looking like "01", "02" etc. What I am not sure of is the convention used here. Why is the format {0:00} and not {00} ? string.Format("{0:00}", int.Parse(testVal) + 1); The first 0 is the placeholder, means the first parameter. 00 is an actual format. For example it could be like this: var result = string.Format("{0:00} - {1:00}", 5, 6); result will be 05 - 06 . So the first 0 is means take the first parameter 5, while 1 means to take parameter 6. The format is {index[,length][