Compatibility with pandas

To convert a LArray object into a pandas DataFrame, the method to_frame() can be used:

In [1]: df = pop.to_frame()

In [2]: df
Out[2]: 
year       2015  2016  2017
age   sex                  
0-9   F     0.0   0.0   0.0
      M     0.0   0.0   0.0
10-17 F     0.0   0.0   0.0
      M     0.0   0.0   0.0
18-66 F     0.0   0.0   0.0
      M     0.0   0.0   0.0
67+   F     0.0   0.0   0.0
      M     0.0   0.0   0.0

Inversely, to convert a DataFrame into a LArray object, use the function aslarray():

In [3]: pop = aslarray(df)

In [4]: pop
Out[4]: 
  age  sex\year  2015  2016  2017
  0-9         F   0.0   0.0   0.0
  0-9         M   0.0   0.0   0.0
10-17         F   0.0   0.0   0.0
10-17         M   0.0   0.0   0.0
18-66         F   0.0   0.0   0.0
18-66         M   0.0   0.0   0.0
  67+         F   0.0   0.0   0.0
  67+         M   0.0   0.0   0.0