title: what to fix to solve the TypeError: an integer is required (got type str)
body: <p>I have a problem with the choice of calculation years.  </p>
  
  <pre><code>python flux2nc.py ../data/output/fluxes/ ../data/output/
      IMPORTANT: ../data/output/fluxes/ SHOULD CONTAIN ONLY FLUXES FILES!!!
      Choose output parameter
      1 - Precipitation
      2 - Evapotranspiration
      3 - Runoff
      4 - Base flow
      5 - Snow Water Equivalent
      6 - Soil moisture
      Choose output (1 a 6)&gt;3
      Enter start year:2011
      End year:2012
      Traceback (most recent call last):
        File "flux2nc.py", line 240, in &lt;module&gt;
          main()
        File "flux2nc.py", line 234, in main
          flux2nc(sys.argv[1],sys.argv[2])
        File "flux2nc.py", line 120, in flux2nc
          inidate = dt.date(start_year,1,1)
      TypeError: an integer is required (got type str)
  </code></pre>
  
  <p>I know that this problem is already posed, but I can't find the exact solution given my limited knowledge on python, and the script is pretty much complicated. </p>
  
  <p>here is the part of the source code, related to my question. </p>
  
  <pre><code># import dependencies
  import sys
  import os, string
  # handle dates...
  import datetime as dt
  # NetCDF and Numeric
  from netCDF4 import *
  from numpy import *
  
      # if the date information is not set get it from user
      if start_year == None:
          # for what date?
          start_year = input("Enter start year:")
      if end_year == None:
          end_year = input("End year:")
  
      # set date information in datetime object
      inidate = dt.date(start_year,1,1)
      enddate = dt.date(end_year,12,31)
  
      # calculate number of days in time series
      days = enddate.toordinal() - inidate.toordinal()+1
  </code></pre>