Python Pandasはバッチ処理に向いてない ref: http://qiita.com/piyo7/items/2d4444d3e8e7d385c809

file0.txt

>>> s = pd.Series([0, 1, 2])
>>> s[2]
2
>>> s[1] = np.nan
>>> s[2]
2.0

file1.txt

def do_something(df):
   foo = df[['bar', 'baz']]  # Is foo a view? A copy? Nobody knows!
   # ... many lines here ...
   foo['quux'] = value       # We don't know whether this will modify df or not!
   return foo

file2.txt

*** glibc detected *** /usr/local/anaconda/bin/python: free(): invalid pointer:

file3.txt

Fatal Python error: GC object already tracked