Template Language Terms in Django

Let’s quickly review some Django Template Language terms

• A template is a text document, or a normal Python string, that is marked up using the Django template language. A template can contain block tags and variables.
  
  
• A block tag is a symbol within a template that does something. This definition is deliberately vague. For example, a block tag can produce content, serve as a control structure (an if statement or for loop), grab content from a database, or enable access to other template tags.
  Block tags are surrounded by {% and %}:
  

  {% if is_logged_in %}
    Thanks for logging in!
  {% else %}
    Please log in.
  {% endif %}

• A variable is a symbol within a template that outputs a value.
  Variable tags are surrounded by {{ and }}:
  

  My first name is {{ first_name }}. My last name is {{ last_name }}.

• A context is a name -> value mapping (similar to a Python dictionary) that is passed to a template.
  
• A template renders a context by replacing the variable “holes” with values from the context and executing all block tags.

Convert Windows-1251 (Cyrillic) to Unicode using Python

Just 4 lines of code to convert some file content from Windows-1251 (Cyrillic) to Unicode with Python

import codecs

f = codecs.open(filename, 'r', 'cp1251')
u = f.read()   # now the contents have been transformed to a Unicode string
out = codecs.open(output, 'w', 'utf-8')
out.write(u)   # and now the contents have been output as UTF-8

The multi valued string regex pattern

Let’s write a regular expression to identify user inputs in the form of two values, separated by either comma or space, such as:   12.6, 3  or  12.6    3 

The condition being this value must be single or integer; spaces should be handled; no need to check empty spaces at the start of end of the string; "12.6" or "12.6," are both not accepted.

This should work (code by les patter)

string pattern = @"\d+(\.\d)?(\s|\,)\s*\d+(\.\d)?";
            string[] tests = {
                                 "12.6, 3",
                                 "12.6    3",
                                 "12.6",
                                 "12.6,",
                                 ", 3",
                                 " 4",
                                 "1, 2.3",
                                 "123, 456",
                              };
            foreach (string test in tests)
                Console.WriteLine("{0}: {1}", Regex.IsMatch(test, pattern), test);
        }