python - Preparing a string by concatenation and accessing its contents -

I want to create a string name with inserting two other small stars and then I want to use his content.

Example:

  teststring = "teststringlength" len ("test" + "string")   
 Length of 'teststring', i.e. "test string lamp" length = 15   
 
 
 I do not know What to do with C, but in Python, you can do this:  
  eval ('len ({} {})' format ('test', 'string')) < / Code>  
 It is not very secure, even if a malicious user If able to provide an arbitrary string, it can run arbitrary python code.  
 Another option  locals () :  
  local () ['test' + 'string']   
 There are some warnings for its use (see for more information; see also Gabe's comment below for possible improvement). / P> 
 Finally, the preferred solution is usually to use a dictionary instead of multiple variables:  
  data = {'teststring': 'teststringlength'} len ( Data ['test' + 'string'])