Lecture 23 - Missing Data.ipynb

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   "source": [
    "import numpy as np\n",
    "import pandas as pd\n",
    "from pandas import Series,DataFrame"
   ]
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   "source": [
    "data = Series(['one','two',np.nan,'four'])"
   ]
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       "0     one\n",
       "1     two\n",
       "2     NaN\n",
       "3    four\n",
       "dtype: object"
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     },
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     "output_type": "execute_result"
    }
   ],
   "source": [
    "data"
   ]
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       "0    False\n",
       "1    False\n",
       "2     True\n",
       "3    False\n",
       "dtype: bool"
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   ],
   "source": [
    "data.isnull()"
   ]
  },
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   },
   "outputs": [
    {
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       "3    four\n",
       "dtype: object"
      ]
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   "source": [
    "data.dropna()"
   ]
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    "data"
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   "source": [
    "dframe = DataFrame([[1,2,3],[np.nan,5,6],[7,np.nan,9],[np.nan,np.nan,np.nan]])"
   ]
  },
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    "clean_dframe = dframe.dropna()"
   ]
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    "npn = np.nan\n",
    "dframe2 = DataFrame([[1,2,3,npn],[2,npn,5,6],[npn,7,npn,9],[1,npn,npn,npn]])"
   ]
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