title: python request.get does form the right url
body: <p>I tried to use python requests sending GET requests. However, I found the url that formed by request.get() doesn't follow the document.</p>
  
  <p>Here is an example:</p>
  
  <pre><code>import requests
  
  root_web_address = 'http://www.amazon.com'
  action_address = '/s/ref=nb_sb_noss'
  
  get_url = root_web_address + action_address
  
  input_1_value_unicode = unicode('search-alias=aps', 'utf-8')
  input_2_value_unicode = unicode('asics', 'utf-8')
  
  get_parameters = {'url':input_1_value_unicode, 'field-keywords':input_2_value_unicode}
  
  r = requests.get(get_url, params = get_parameters)
  
  print r.url
  </code></pre>
  
  <p>The expected URL should be:</p>
  
  <pre><code>http://www.amazon.com/s/ref=nb_sb_noss?url=search-alias%3Daps&amp;field-keywords=asics
  </code></pre>
  
  <p>However, the print r.url gives me:</p>
  
  <pre><code>http://www.amazon.com/s?ie=UTF8&amp;page=1&amp;rh=i%3Aaps%2Ck%3Aasics
  </code></pre>
  
  <p>Why?</p>