dictionary use
# example
d={'var1':1, 'var2':2}
# GET INDEX AND VALUES
print d.keys() # ['var1', 'var2']
print d.values() # [1, 2]
# FIND INDEX BY VALUE
mydict = {'george':16,'amber':19}
print(list(mydict.keys())[list(mydict.values()).index(16)]) # Prints george