Series align bug.ipynb

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   "source": [
    "import pandas as pd\n",
    "import numpy as np"
   ]
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   "cell_type": "code",
   "execution_count": 7,
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   "source": [
    "idx = pd.MultiIndex.from_product([range(2), range(3), range(2)],\n",
    "                                 names=('a', 'b', 'c'))"
   ]
  },
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   "cell_type": "code",
   "execution_count": 13,
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   "source": [
    "s1 = pd.Series(np.arange(12), idx)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 18,
   "metadata": {
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   "outputs": [],
   "source": [
    "s2 = pd.Series(np.arange(2), pd.Index(range(2), name='b'))"
   ]
  },
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     "data": {
      "text/plain": [
       "a  b  c\n",
       "0  0  0     0\n",
       "      1     1\n",
       "   1  0     2\n",
       "      1     3\n",
       "   2  0     4\n",
       "      1     5\n",
       "1  0  0     6\n",
       "      1     7\n",
       "   1  0     8\n",
       "      1     9\n",
       "   2  0    10\n",
       "      1    11\n",
       "dtype: int32"
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     "execution_count": 19,
     "metadata": {},
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   "source": [
    "s1"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 20,
   "metadata": {
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   "outputs": [
    {
     "data": {
      "text/plain": [
       "b\n",
       "0    0\n",
       "1    1\n",
       "dtype: int32"
      ]
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     "execution_count": 20,
     "metadata": {},
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    "s2"
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   "execution_count": 25,
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   "outputs": [],
   "source": [
    "# the join \"direction\" is reversed ! it did a \"right\" join instead of \"left\"\n",
    "x, y = s1.align(s2, join='left')"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 26,
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     "data": {
      "text/plain": [
       "a  b  c\n",
       "0  0  0    0\n",
       "      1    1\n",
       "   1  0    2\n",
       "      1    3\n",
       "1  0  0    6\n",
       "      1    7\n",
       "   1  0    8\n",
       "      1    9\n",
       "dtype: int32"
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     "execution_count": 26,
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   "source": [
    "x"
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     "data": {
      "text/plain": [
       "a  b  c\n",
       "0  0  0    0\n",
       "      1    0\n",
       "   1  0    1\n",
       "      1    1\n",
       "1  0  0    0\n",
       "      1    0\n",
       "   1  0    1\n",
       "      1    1\n",
       "dtype: int32"
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     "execution_count": 27,
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   "source": [
    "y"
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  {
   "cell_type": "code",
   "execution_count": 28,
   "metadata": {
    "collapsed": false
   },
   "outputs": [],
   "source": [
    "# and if I do a right join, I get a left join ! :)\n",
    "x, y = s1.align(s2, join='right')"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 29,
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     "data": {
      "text/plain": [
       "a  b  c\n",
       "0  0  0     0\n",
       "      1     1\n",
       "   1  0     2\n",
       "      1     3\n",
       "   2  0     4\n",
       "      1     5\n",
       "1  0  0     6\n",
       "      1     7\n",
       "   1  0     8\n",
       "      1     9\n",
       "   2  0    10\n",
       "      1    11\n",
       "dtype: int32"
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    "x"
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       "a  b  c\n",
       "0  0  0     0\n",
       "      1     0\n",
       "   1  0     1\n",
       "      1     1\n",
       "   2  0   NaN\n",
       "      1   NaN\n",
       "1  0  0     0\n",
       "      1     0\n",
       "   1  0     1\n",
       "      1     1\n",
       "   2  0   NaN\n",
       "      1   NaN\n",
       "dtype: float64"
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     "execution_count": 30,
     "metadata": {},
     "output_type": "execute_result"
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    "y"
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   "execution_count": null,
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   "source": []
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