title: Python3 Typerror: replace() argument 1 must be str, not int
body: <p>I've been trying a few days now to get this code to work on MacOS but with no success. Can you please have a look at and see what I'm missing?</p>
  
  <p>Running python 3.6 and I've uploaded the whole code. Thanks a lot</p>
  
  <pre><code>#!/usr/bin/env python3
  from __future__ import print_function
  try:
      import pymarketcap
      import decimal
      from operator import itemgetter
      import argparse
  except Exception as e:
      print('Make sure to install {0} (pip3 install {0}).'.format(str(e).split("'")[1]))
      exit()
  
  # arguments and setup
  parser = argparse.ArgumentParser()
  parser.add_argument('-m','--minimum_vol',type=float,help='Minimum Percent volume per exchange to have to count',default=1)
  parser.add_argument('-p','--pairs',nargs='*',default=[],help='Pairs the coins can be arbitraged with - default=all')
  parser.add_argument('-c','--coins_shown',type=int,default=10,help='Number of coins to show')
  parser.add_argument('-e','--exchanges',nargs='*',help='Acceptable Exchanges - default=all',default=[])
  parser.add_argument('-s','--simple',help='Toggle off errors and settings',default=False,action="store_true")
  args = parser.parse_args()
  cmc = pymarketcap.Pymarketcap()
  info = []
  count = 1
  lowercase_exchanges = [x.lower() for x in args.exchanges]
  all_exchanges = not bool(args.exchanges)
  all_trading_pairs = not bool(args.pairs)
  coin_format = '{: &lt;25} {: &gt;6}% {: &gt;10} {: &gt;15} {: &lt;10} {: &lt;10} {: &lt;15} {: &lt;5}'
  
  if not args.simple:
      print('CURRENT SETTINGS\n* MINIMUM_PERCENT_VOL:{}\n* TRADING_PAIRS:{}\n* COINS_SHOWN:{}\n* EXCHANGES:{}\n* ALL_TRADING_PAIRS:{}\n* ALL_EXCHANGES:{}\n'.format(args.minimum_vol,args.pairs,args.coins_shown,lowercase_exchanges,all_trading_pairs,all_exchanges))
  # retrieve coin data
  for coin in cmc.ticker():
      try:
          markets = cmc.markets(coin["id"])
      except Exception as e:
          markets = cmc.markets(coin["symbol"])
      best_price = 0
  
      best_exchange = ''
      best_pair = ''
      worst_price = 999999
      worst_exchange = ''
      worst_pair = ''
      has_markets = False
      for market in markets:
          trades_into = market["pair"].replace (coin["symbol"]," ").replace("-"," ")
          if market['percent_volume'] &gt;= args.minimum_vol and market['updated'] and (trades_into in args.pairs or all_trading_pairs) and (market['exchange'].lower() in lowercase_exchanges or all_exchanges):
              has_markets = True
              if market['price_usd'] &gt;= best_price:
                  best_price = market['price_usd']
                  best_exchange = market['exchange']
                  best_pair = trades_into
              if market['price_usd'] &lt;= worst_price:
                  worst_price = market['price_usd']
                  worst_exchange = market['exchange']
                  worst_pair = trades_into
      if has_markets:
          info.append([coin['name'],round((best_price/worst_price-1)*100,2),worst_price,worst_exchange,worst_pair,best_price,best_exchange,best_pair])
      elif not args.simple:
          print(coin['name'],'had no markets that fit the criteria.')
  
      print('[{}/100]'.format(count),end='\r')
      count += 1
  
  # show data
  info = sorted(info,key=itemgetter(1))[::-1]
  print(coin_format.format("COIN","CHANGE","BUY PRICE","BUY AT","BUY WITH","SELL PRICE","SELL AT","SELL WITH"))
  for coin in info[0:args.coins_shown]:
      print(coin_format.format(*coin))#
  </code></pre>
  
  <p>also link - <a href="https://gist.github.com/anonymous/ec0643e0b27f33cf628fdafce29a698c" rel="nofollow noreferrer">https://gist.github.com/anonymous/ec0643e0b27f33cf628fdafce29a698c</a></p>
  
  <p>The error that I keep getting is this :</p>
  
  <pre><code>Traceback (most recent call last):
    File "./run", line 45, in &lt;module&gt;
      trades_into = market["pair"].replace(coin["symbol"],"").replace("-","")
  TypeError: replace() argument 1 must be str, not int
  </code></pre>
  
  <p>Really appreciate your help with this.</p>