This Gist is focused on converting decimal degrees length to meters (or vise versa) for a specific point on the globe. It is based on an approximation and only should be used as a general measurement (errors around 10 m).

dd2meter.py

import numpy as np

def dd2meters(inPt,scale=0.1):
    """Function to convert decimal degrees to meters based on the approximation
    given by: https://en.wikipedia.org/wiki/Geographic_coordinate_system
    
    Args:
        inPt (list or array): A Y,X point provided in geographic coordinates
        in that order.

    Keywords:
        scale (int): Resolution of the raster value to covert into meters,
        must be in decimal degrees.
        
    Returns:
        list: List of Y,X resolution values converted from meters to decimal degrees
        
    """

    lat = inPt[0] #get latitude value
    
    radLat = np.deg2rad(lat) #convert degree latitude to radians
    
    a = 6378137 #radius of Earth in meters
    
    ba = 0.99664719 #constant of b/a
    
    ss = np.arctan(ba*np.tan(radLat)) #calculate the reduced latitude
    
    #factor to convert meters to decimal degrees for X axis
    xfct = (np.pi/180)*a*np.cos(ss)
     
    #factor to convert meters to decimal degrees for Y axis
    yfct = (111132.92-559.82*np.cos(2*radLat)+1.175*np.cos(4*radLat)-
              0.0023*np.cos(6*radLat))
        
    #get meter resolution
    y_meters = scale * yfct
    x_meters = scale * xfct
    
    #return list of converted resolution values
    return [y_meters,x_meters]
    
def main():
  inPt = [75,0]
  outScale = dd2meters(inPt)

  print outScale
  
  return

if __name__ == "__main__":
  main()

meter2dd.py

import numpy as np

def meters2dd(inPt,scale=30):
    """Function to convert meters to decimal degrees based on the approximation
    given by: https://en.wikipedia.org/wiki/Geographic_coordinate_system
    
    Args:
        inPt (list or array): A Y,X point provided in geographic coordinates
        in that order.

    Keywords:
        scale (int): Resolution of the raster value to covert into decimal 
        degrees, must be in meters.
        
    Returns:
        list: List of Y,X resolution values converted from meters to decimal degrees
        
    """

    lat = inPt[0] #get latitude value
    
    radLat = np.deg2rad(lat) #convert degree latitude to radians
    
    a = 6378137 #radius of Earth in meters
    
    ba = 0.99664719 #constant of b/a
    
    ss = np.arctan(ba*np.tan(radLat)) #calculate the reduced latitude
    
    #factor to convert meters to decimal degrees for X axis
    xfct = (np.pi/180)*a*np.cos(ss)
     
    #factor to convert meters to decimal degrees for Y axis
    yfct = (111132.92-559.82*np.cos(2*radLat)+1.175*np.cos(4*radLat)-
              0.0023*np.cos(6*radLat))
        
    #get decimal degree resolution
    ydd = scale / yfct
    xdd = scale / xfct
    
    #return list of converted resolution values
    return [ydd,xdd]

def main():
  inPt = [75,0]
  outScale = meters2dd(inPt)

  print outScale
  
  return

if __name__ == "__main__":
  main()