title: Extracting data from .nc file by latitude and longitude in python
body: <p>I have gridded datasets in .nc format. I want to extract data on the basis of latitude and longitude. Latitude and longitude of my datasets are shown below:</p>
  
  <pre><code>import netCDF4
  from netCDF4 import Dataset
  f= Dataset('data.nc')
  f.variables['lat'][:]
  array([ 31.5,  30.5,  29.5,  28.5,  27.5,  26.5,  25.5,  24.5,  23.5,
          22.5,  21.5,  20.5,  19.5,  18.5], dtype=float32)
  
  f.variables['lon'][:]
  array([ 60.5,  61.5,  62.5,  63.5,  64.5,  65.5,  66.5,  67.5,  68.5,
          69.5,  70.5,  71.5,  72.5,  73.5,  74.5,  75.5,  76.5,  77.5,
          78.5,  79.5,  80.5,  81.5,  82.5,  83.5,  84.5,  85.5,  86.5,
          87.5,  88.5,  89.5,  90.5,  91.5], dtype=float32)
  </code></pre>
  
  <p>suppose I want to extract the data for lat = 29.5 and lon = 65.5
  then which code is correct?</p>
  
  <pre><code>f.variables['temp'][:,2,5]
  </code></pre>
  
  <p>or </p>
  
  <pre><code>f.variables['temp'][:,29.5,65.5]
  </code></pre>
  
  <p>yours suggestion will be highly appreciated!</p>