title: How to place percentage orders with Binance API and Python-CCXT?
body: <p>I'm playing with Binance API to make my trading bot with Python 3.6. and <a href="https://github.com/ccxt/ccxt" rel="noreferrer">CCXT library</a> (here you find the <a href="https://ccxt.readthedocs.io/en/latest/" rel="noreferrer">docs</a> ).</p>
  
  <p>One very useful thing they have in their site is the capability to place orders for a percentage of your current balance:</p>
  
  <p>for example if I'm lookin at <code>BTC/USDT</code> crypto coin pair, and I have <code>50 USDT</code> on my account, I can choose between buying <code>N</code> amount of <code>BTC</code> or using <code>100%</code> of my account's <code>USDT</code> for buying, consequently buying the maximum amount of <code>BTC</code> I can.</p>
  
  <p>I read the docs many times, but I can't find the option to do these "percentage of balance" orders with the API in any way: the only thing I can do is passing a <code>float</code> to the order function.
  This is how i place orders now:</p>
  
  <pre class="lang-py prettyprint-override"><code>amount = 0.001
  symbol = "BTC/USDT"
  
  def buyorder(amount, symbol): # this makes a market order taking in the amount I defined before, for the pair defined by "symbol"
  
      type = 'market'  # or 'limit'
      side = 'buy'     # or 'sell'
      params = {}      # extra params and overrides if needed
      order = exchange.create_order(symbol, type, side, amount, params)
  </code></pre>
  
  <p>Do anyone know if there is a built-in capability to do 
  a percentage order? If API gives no way to do so, would you suggest some workarounds?</p>
  
  <p>I want to be able to give to the API percentage of my current balance as an <code>amount</code>, so I can always use the full of it without having to update when fees are detracted</p>