selecting a specific column from multiple files and save it iteratively.ipynb

{
 "cells": [
  {
   "cell_type": "code",
   "execution_count": 3,
   "id": "c8696673",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
       "<div>\n",
       "<style scoped>\n",
       "    .dataframe tbody tr th:only-of-type {\n",
       "        vertical-align: middle;\n",
       "    }\n",
       "\n",
       "    .dataframe tbody tr th {\n",
       "        vertical-align: top;\n",
       "    }\n",
       "\n",
       "    .dataframe thead th {\n",
       "        text-align: right;\n",
       "    }\n",
       "</style>\n",
       "<table border=\"1\" class=\"dataframe\">\n",
       "  <thead>\n",
       "    <tr style=\"text-align: right;\">\n",
       "      <th></th>\n",
       "      <th>acceleration from the chest sensor (X axis)</th>\n",
       "      <th>acceleration from the chest sensor (Y axis)</th>\n",
       "      <th>acceleration from the chest sensor (Z axis)</th>\n",
       "      <th>electrocardiogram signal (lead 1)</th>\n",
       "      <th>electrocardiogram signal (lead 2)</th>\n",
       "      <th>acceleration from the left-ankle sensor (X axis)</th>\n",
       "      <th>acceleration from the left-ankle sensor (Y axis)</th>\n",
       "      <th>acceleration from the left-ankle sensor (Z axis)</th>\n",
       "      <th>gyro from the left-ankle sensor (X axis)</th>\n",
       "      <th>gyro from the left-ankle sensor (Y axis)</th>\n",
       "      <th>...</th>\n",
       "      <th>acceleration from the right-lower-arm sensor (X axis)</th>\n",
       "      <th>acceleration from the right-lower-arm sensor (Y axis)</th>\n",
       "      <th>acceleration from the right-lower-arm sensor (Z axis)</th>\n",
       "      <th>gyro from the right-lower-arm sensor (X axis)</th>\n",
       "      <th>gyro from the right-lower-arm sensor (Y axis)</th>\n",
       "      <th>gyro from the right-lower-arm sensor (Z axis)</th>\n",
       "      <th>magnetometer from the right-lower-arm sensor (X axis)</th>\n",
       "      <th>magnetometer from the right-lower-arm sensor (Y axis)</th>\n",
       "      <th>magnetometer from the right-lower-arm sensor (Z axis)</th>\n",
       "      <th>Label</th>\n",
       "    </tr>\n",
       "  </thead>\n",
       "  <tbody>\n",
       "    <tr>\n",
       "      <th>0</th>\n",
       "      <td>-9.8184</td>\n",
       "      <td>0.009971</td>\n",
       "      <td>0.29563</td>\n",
       "      <td>0.004186</td>\n",
       "      <td>0.004186</td>\n",
       "      <td>2.1849</td>\n",
       "      <td>-9.6967</td>\n",
       "      <td>0.63077</td>\n",
       "      <td>0.103900</td>\n",
       "      <td>-0.84053</td>\n",
       "      <td>...</td>\n",
       "      <td>-8.6499</td>\n",
       "      <td>-4.57810</td>\n",
       "      <td>0.187760</td>\n",
       "      <td>-0.44902</td>\n",
       "      <td>-1.01030</td>\n",
       "      <td>0.034483</td>\n",
       "      <td>-2.35000</td>\n",
       "      <td>-1.610200</td>\n",
       "      <td>-0.030899</td>\n",
       "      <td>0.0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>1</th>\n",
       "      <td>-9.8489</td>\n",
       "      <td>0.524040</td>\n",
       "      <td>0.37348</td>\n",
       "      <td>0.004186</td>\n",
       "      <td>0.016745</td>\n",
       "      <td>2.3876</td>\n",
       "      <td>-9.5080</td>\n",
       "      <td>0.68389</td>\n",
       "      <td>0.085343</td>\n",
       "      <td>-0.83865</td>\n",
       "      <td>...</td>\n",
       "      <td>-8.6275</td>\n",
       "      <td>-4.31980</td>\n",
       "      <td>0.023595</td>\n",
       "      <td>-0.44902</td>\n",
       "      <td>-1.01030</td>\n",
       "      <td>0.034483</td>\n",
       "      <td>-2.16320</td>\n",
       "      <td>-0.882540</td>\n",
       "      <td>0.326570</td>\n",
       "      <td>0.0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>2</th>\n",
       "      <td>-9.6602</td>\n",
       "      <td>0.181850</td>\n",
       "      <td>0.43742</td>\n",
       "      <td>0.016745</td>\n",
       "      <td>0.037677</td>\n",
       "      <td>2.4086</td>\n",
       "      <td>-9.5674</td>\n",
       "      <td>0.68113</td>\n",
       "      <td>0.085343</td>\n",
       "      <td>-0.83865</td>\n",
       "      <td>...</td>\n",
       "      <td>-8.5055</td>\n",
       "      <td>-4.27720</td>\n",
       "      <td>0.275720</td>\n",
       "      <td>-0.44902</td>\n",
       "      <td>-1.01030</td>\n",
       "      <td>0.034483</td>\n",
       "      <td>-1.61750</td>\n",
       "      <td>-0.165620</td>\n",
       "      <td>-0.030693</td>\n",
       "      <td>0.0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>3</th>\n",
       "      <td>-9.6507</td>\n",
       "      <td>0.214220</td>\n",
       "      <td>0.24033</td>\n",
       "      <td>0.079540</td>\n",
       "      <td>0.117220</td>\n",
       "      <td>2.1814</td>\n",
       "      <td>-9.4301</td>\n",
       "      <td>0.55031</td>\n",
       "      <td>0.085343</td>\n",
       "      <td>-0.83865</td>\n",
       "      <td>...</td>\n",
       "      <td>-8.6279</td>\n",
       "      <td>-4.31630</td>\n",
       "      <td>0.367520</td>\n",
       "      <td>-0.45686</td>\n",
       "      <td>-1.00820</td>\n",
       "      <td>0.025862</td>\n",
       "      <td>-1.07710</td>\n",
       "      <td>0.006945</td>\n",
       "      <td>-0.382620</td>\n",
       "      <td>0.0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>4</th>\n",
       "      <td>-9.7030</td>\n",
       "      <td>0.303890</td>\n",
       "      <td>0.31156</td>\n",
       "      <td>0.221870</td>\n",
       "      <td>0.205130</td>\n",
       "      <td>2.4173</td>\n",
       "      <td>-9.3889</td>\n",
       "      <td>0.71098</td>\n",
       "      <td>0.085343</td>\n",
       "      <td>-0.83865</td>\n",
       "      <td>...</td>\n",
       "      <td>-8.7008</td>\n",
       "      <td>-4.14590</td>\n",
       "      <td>0.407290</td>\n",
       "      <td>-0.45686</td>\n",
       "      <td>-1.00820</td>\n",
       "      <td>0.025862</td>\n",
       "      <td>-0.53684</td>\n",
       "      <td>0.175900</td>\n",
       "      <td>-1.095500</td>\n",
       "      <td>0.0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>...</th>\n",
       "      <td>...</td>\n",
       "      <td>...</td>\n",
       "      <td>...</td>\n",
       "      <td>...</td>\n",
       "      <td>...</td>\n",
       "      <td>...</td>\n",
       "      <td>...</td>\n",
       "      <td>...</td>\n",
       "      <td>...</td>\n",
       "      <td>...</td>\n",
       "      <td>...</td>\n",
       "      <td>...</td>\n",
       "      <td>...</td>\n",
       "      <td>...</td>\n",
       "      <td>...</td>\n",
       "      <td>...</td>\n",
       "      <td>...</td>\n",
       "      <td>...</td>\n",
       "      <td>...</td>\n",
       "      <td>...</td>\n",
       "      <td>...</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>161276</th>\n",
       "      <td>-9.5201</td>\n",
       "      <td>0.751360</td>\n",
       "      <td>-3.84820</td>\n",
       "      <td>-0.104660</td>\n",
       "      <td>-0.025118</td>\n",
       "      <td>2.0773</td>\n",
       "      <td>-9.5717</td>\n",
       "      <td>2.24010</td>\n",
       "      <td>-0.903530</td>\n",
       "      <td>-0.96998</td>\n",
       "      <td>...</td>\n",
       "      <td>-4.4840</td>\n",
       "      <td>5.07440</td>\n",
       "      <td>6.441200</td>\n",
       "      <td>-0.65490</td>\n",
       "      <td>0.54415</td>\n",
       "      <td>0.676720</td>\n",
       "      <td>26.90100</td>\n",
       "      <td>-2.929500</td>\n",
       "      <td>-30.119000</td>\n",
       "      <td>0.0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>161277</th>\n",
       "      <td>-9.3682</td>\n",
       "      <td>1.239600</td>\n",
       "      <td>-3.02530</td>\n",
       "      <td>-0.138150</td>\n",
       "      <td>-0.079540</td>\n",
       "      <td>1.7497</td>\n",
       "      <td>-9.3127</td>\n",
       "      <td>2.39560</td>\n",
       "      <td>-0.903530</td>\n",
       "      <td>-0.96998</td>\n",
       "      <td>...</td>\n",
       "      <td>-3.1657</td>\n",
       "      <td>0.98528</td>\n",
       "      <td>7.528400</td>\n",
       "      <td>-0.65490</td>\n",
       "      <td>0.54415</td>\n",
       "      <td>0.676720</td>\n",
       "      <td>17.28800</td>\n",
       "      <td>5.330800</td>\n",
       "      <td>-30.393000</td>\n",
       "      <td>0.0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>161278</th>\n",
       "      <td>-8.6702</td>\n",
       "      <td>1.185900</td>\n",
       "      <td>-3.01960</td>\n",
       "      <td>-0.066981</td>\n",
       "      <td>-0.050235</td>\n",
       "      <td>1.8910</td>\n",
       "      <td>-9.3342</td>\n",
       "      <td>2.21890</td>\n",
       "      <td>-0.903530</td>\n",
       "      <td>-0.96998</td>\n",
       "      <td>...</td>\n",
       "      <td>-1.0351</td>\n",
       "      <td>-0.85876</td>\n",
       "      <td>6.123700</td>\n",
       "      <td>-0.65490</td>\n",
       "      <td>0.54415</td>\n",
       "      <td>0.676720</td>\n",
       "      <td>17.43000</td>\n",
       "      <td>19.502000</td>\n",
       "      <td>-28.727000</td>\n",
       "      <td>0.0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>161279</th>\n",
       "      <td>-8.7211</td>\n",
       "      <td>1.205600</td>\n",
       "      <td>-2.00730</td>\n",
       "      <td>-0.012559</td>\n",
       "      <td>0.025118</td>\n",
       "      <td>2.3099</td>\n",
       "      <td>-9.2537</td>\n",
       "      <td>2.35210</td>\n",
       "      <td>-0.909090</td>\n",
       "      <td>-0.97186</td>\n",
       "      <td>...</td>\n",
       "      <td>-2.9315</td>\n",
       "      <td>-1.33840</td>\n",
       "      <td>5.162200</td>\n",
       "      <td>-0.65490</td>\n",
       "      <td>0.54415</td>\n",
       "      <td>0.676720</td>\n",
       "      <td>16.53500</td>\n",
       "      <td>19.779000</td>\n",
       "      <td>-20.084000</td>\n",
       "      <td>0.0</td>\n",
       "    </tr>\n",
       "    <tr>\n",
       "      <th>161280</th>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>...</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "      <td>NaN</td>\n",
       "    </tr>\n",
       "  </tbody>\n",
       "</table>\n",
       "<p>161281 rows × 24 columns</p>\n",
       "</div>"
      ],
      "text/plain": [
       "        acceleration from the chest sensor (X axis)  \\\n",
       "0                                           -9.8184   \n",
       "1                                           -9.8489   \n",
       "2                                           -9.6602   \n",
       "3                                           -9.6507   \n",
       "4                                           -9.7030   \n",
       "...                                             ...   \n",
       "161276                                      -9.5201   \n",
       "161277                                      -9.3682   \n",
       "161278                                      -8.6702   \n",
       "161279                                      -8.7211   \n",
       "161280                                          NaN   \n",
       "\n",
       "        acceleration from the chest sensor (Y axis)  \\\n",
       "0                                          0.009971   \n",
       "1                                          0.524040   \n",
       "2                                          0.181850   \n",
       "3                                          0.214220   \n",
       "4                                          0.303890   \n",
       "...                                             ...   \n",
       "161276                                     0.751360   \n",
       "161277                                     1.239600   \n",
       "161278                                     1.185900   \n",
       "161279                                     1.205600   \n",
       "161280                                          NaN   \n",
       "\n",
       "        acceleration from the chest sensor (Z axis)  \\\n",
       "0                                           0.29563   \n",
       "1                                           0.37348   \n",
       "2                                           0.43742   \n",
       "3                                           0.24033   \n",
       "4                                           0.31156   \n",
       "...                                             ...   \n",
       "161276                                     -3.84820   \n",
       "161277                                     -3.02530   \n",
       "161278                                     -3.01960   \n",
       "161279                                     -2.00730   \n",
       "161280                                          NaN   \n",
       "\n",
       "        electrocardiogram signal (lead 1)  electrocardiogram signal (lead 2)  \\\n",
       "0                                0.004186                           0.004186   \n",
       "1                                0.004186                           0.016745   \n",
       "2                                0.016745                           0.037677   \n",
       "3                                0.079540                           0.117220   \n",
       "4                                0.221870                           0.205130   \n",
       "...                                   ...                                ...   \n",
       "161276                          -0.104660                          -0.025118   \n",
       "161277                          -0.138150                          -0.079540   \n",
       "161278                          -0.066981                          -0.050235   \n",
       "161279                          -0.012559                           0.025118   \n",
       "161280                                NaN                                NaN   \n",
       "\n",
       "        acceleration from the left-ankle sensor (X axis)  \\\n",
       "0                                                 2.1849   \n",
       "1                                                 2.3876   \n",
       "2                                                 2.4086   \n",
       "3                                                 2.1814   \n",
       "4                                                 2.4173   \n",
       "...                                                  ...   \n",
       "161276                                            2.0773   \n",
       "161277                                            1.7497   \n",
       "161278                                            1.8910   \n",
       "161279                                            2.3099   \n",
       "161280                                               NaN   \n",
       "\n",
       "        acceleration from the left-ankle sensor (Y axis)  \\\n",
       "0                                                -9.6967   \n",
       "1                                                -9.5080   \n",
       "2                                                -9.5674   \n",
       "3                                                -9.4301   \n",
       "4                                                -9.3889   \n",
       "...                                                  ...   \n",
       "161276                                           -9.5717   \n",
       "161277                                           -9.3127   \n",
       "161278                                           -9.3342   \n",
       "161279                                           -9.2537   \n",
       "161280                                               NaN   \n",
       "\n",
       "        acceleration from the left-ankle sensor (Z axis)  \\\n",
       "0                                                0.63077   \n",
       "1                                                0.68389   \n",
       "2                                                0.68113   \n",
       "3                                                0.55031   \n",
       "4                                                0.71098   \n",
       "...                                                  ...   \n",
       "161276                                           2.24010   \n",
       "161277                                           2.39560   \n",
       "161278                                           2.21890   \n",
       "161279                                           2.35210   \n",
       "161280                                               NaN   \n",
       "\n",
       "        gyro from the left-ankle sensor (X axis)  \\\n",
       "0                                       0.103900   \n",
       "1                                       0.085343   \n",
       "2                                       0.085343   \n",
       "3                                       0.085343   \n",
       "4                                       0.085343   \n",
       "...                                          ...   \n",
       "161276                                 -0.903530   \n",
       "161277                                 -0.903530   \n",
       "161278                                 -0.903530   \n",
       "161279                                 -0.909090   \n",
       "161280                                       NaN   \n",
       "\n",
       "        gyro from the left-ankle sensor (Y axis)  ...  \\\n",
       "0                                       -0.84053  ...   \n",
       "1                                       -0.83865  ...   \n",
       "2                                       -0.83865  ...   \n",
       "3                                       -0.83865  ...   \n",
       "4                                       -0.83865  ...   \n",
       "...                                          ...  ...   \n",
       "161276                                  -0.96998  ...   \n",
       "161277                                  -0.96998  ...   \n",
       "161278                                  -0.96998  ...   \n",
       "161279                                  -0.97186  ...   \n",
       "161280                                       NaN  ...   \n",
       "\n",
       "        acceleration from the right-lower-arm sensor (X axis)  \\\n",
       "0                                                 -8.6499       \n",
       "1                                                 -8.6275       \n",
       "2                                                 -8.5055       \n",
       "3                                                 -8.6279       \n",
       "4                                                 -8.7008       \n",
       "...                                                   ...       \n",
       "161276                                            -4.4840       \n",
       "161277                                            -3.1657       \n",
       "161278                                            -1.0351       \n",
       "161279                                            -2.9315       \n",
       "161280                                                NaN       \n",
       "\n",
       "        acceleration from the right-lower-arm sensor (Y axis)  \\\n",
       "0                                                -4.57810       \n",
       "1                                                -4.31980       \n",
       "2                                                -4.27720       \n",
       "3                                                -4.31630       \n",
       "4                                                -4.14590       \n",
       "...                                                   ...       \n",
       "161276                                            5.07440       \n",
       "161277                                            0.98528       \n",
       "161278                                           -0.85876       \n",
       "161279                                           -1.33840       \n",
       "161280                                                NaN       \n",
       "\n",
       "        acceleration from the right-lower-arm sensor (Z axis)  \\\n",
       "0                                                0.187760       \n",
       "1                                                0.023595       \n",
       "2                                                0.275720       \n",
       "3                                                0.367520       \n",
       "4                                                0.407290       \n",
       "...                                                   ...       \n",
       "161276                                           6.441200       \n",
       "161277                                           7.528400       \n",
       "161278                                           6.123700       \n",
       "161279                                           5.162200       \n",
       "161280                                                NaN       \n",
       "\n",
       "        gyro from the right-lower-arm sensor (X axis)  \\\n",
       "0                                            -0.44902   \n",
       "1                                            -0.44902   \n",
       "2                                            -0.44902   \n",
       "3                                            -0.45686   \n",
       "4                                            -0.45686   \n",
       "...                                               ...   \n",
       "161276                                       -0.65490   \n",
       "161277                                       -0.65490   \n",
       "161278                                       -0.65490   \n",
       "161279                                       -0.65490   \n",
       "161280                                            NaN   \n",
       "\n",
       "        gyro from the right-lower-arm sensor (Y axis)  \\\n",
       "0                                            -1.01030   \n",
       "1                                            -1.01030   \n",
       "2                                            -1.01030   \n",
       "3                                            -1.00820   \n",
       "4                                            -1.00820   \n",
       "...                                               ...   \n",
       "161276                                        0.54415   \n",
       "161277                                        0.54415   \n",
       "161278                                        0.54415   \n",
       "161279                                        0.54415   \n",
       "161280                                            NaN   \n",
       "\n",
       "        gyro from the right-lower-arm sensor (Z axis)  \\\n",
       "0                                            0.034483   \n",
       "1                                            0.034483   \n",
       "2                                            0.034483   \n",
       "3                                            0.025862   \n",
       "4                                            0.025862   \n",
       "...                                               ...   \n",
       "161276                                       0.676720   \n",
       "161277                                       0.676720   \n",
       "161278                                       0.676720   \n",
       "161279                                       0.676720   \n",
       "161280                                            NaN   \n",
       "\n",
       "        magnetometer from the right-lower-arm sensor (X axis)  \\\n",
       "0                                                -2.35000       \n",
       "1                                                -2.16320       \n",
       "2                                                -1.61750       \n",
       "3                                                -1.07710       \n",
       "4                                                -0.53684       \n",
       "...                                                   ...       \n",
       "161276                                           26.90100       \n",
       "161277                                           17.28800       \n",
       "161278                                           17.43000       \n",
       "161279                                           16.53500       \n",
       "161280                                                NaN       \n",
       "\n",
       "        magnetometer from the right-lower-arm sensor (Y axis)  \\\n",
       "0                                               -1.610200       \n",
       "1                                               -0.882540       \n",
       "2                                               -0.165620       \n",
       "3                                                0.006945       \n",
       "4                                                0.175900       \n",
       "...                                                   ...       \n",
       "161276                                          -2.929500       \n",
       "161277                                           5.330800       \n",
       "161278                                          19.502000       \n",
       "161279                                          19.779000       \n",
       "161280                                                NaN       \n",
       "\n",
       "        magnetometer from the right-lower-arm sensor (Z axis)  Label  \n",
       "0                                               -0.030899        0.0  \n",
       "1                                                0.326570        0.0  \n",
       "2                                               -0.030693        0.0  \n",
       "3                                               -0.382620        0.0  \n",
       "4                                               -1.095500        0.0  \n",
       "...                                                   ...        ...  \n",
       "161276                                         -30.119000        0.0  \n",
       "161277                                         -30.393000        0.0  \n",
       "161278                                         -28.727000        0.0  \n",
       "161279                                         -20.084000        0.0  \n",
       "161280                                                NaN        NaN  \n",
       "\n",
       "[161281 rows x 24 columns]"
      ]
     },
     "execution_count": 3,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "import os\n",
    "import pandas as pd\n",
    "import numpy as np\n",
    "filepath = 'C:/Users/Ewunetie/OneDrive - University of Gondar,/2022-2023 files/Courses/Project/data/Online data/2 MHEALTH Dataset Data Set CSV/data/mHealth_subject1.csv'\n",
    "df=pd.read_csv(filepath)\n",
    "df"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 6,
   "id": "27d22659",
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "0         0.004186\n",
       "1         0.016745\n",
       "2         0.037677\n",
       "3         0.117220\n",
       "4         0.205130\n",
       "            ...   \n",
       "161276   -0.025118\n",
       "161277   -0.079540\n",
       "161278   -0.050235\n",
       "161279    0.025118\n",
       "161280         NaN\n",
       "Name: electrocardiogram signal (lead 2), Length: 161281, dtype: float64"
      ]
     },
     "execution_count": 6,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "df1=df['electrocardiogram signal (lead 2)']\n",
    "df1"
   ]
  },
  {
   "cell_type": "markdown",
   "id": "b2b4a859",
   "metadata": {},
   "source": [
    "Selecting specific column iteratively and write to csv"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 4,
   "id": "66387c1e",
   "metadata": {},
   "outputs": [],
   "source": [
    "import pandas as pd\n",
    "import os\n",
    "#import xlrd # module for reading and writting excel files\n",
    "# creating empty dataframe for intializing and storing the value after each iteration\n",
    "folder_path = 'C:/Users/Ewunetie/OneDrive - University of Gondar,/2022-2023 files/Courses/ML Project/Data/Online data/3 MIT-BIH Arrhythmia Database (Simple CSVs)/row'\n",
    "output_path = 'C:/Users/Ewunetie/OneDrive - University of Gondar,/2022-2023 files/Courses/ML Project/Data/Online data/3 MIT-BIH Arrhythmia Database (Simple CSVs)/Lead II'\n",
    "files = os.listdir(folder_path)\n",
    "for file_name in files:\n",
    "    # Check if the file has a .mat extension\n",
    "    if file_name.endswith('.csv'):\n",
    "        # Construct the full path for the .mat file\n",
    "        csv_file_path = os.path.join(folder_path, file_name)        \n",
    "        # Load data from the .csv file\n",
    "        csv_data = pd.read_csv(csv_file_path)\n",
    "        \n",
    "        # Selecting the specific column with the column header electrocardiogram signal (lead 2)\n",
    "        df1=csv_data['MLII']\n",
    "                \n",
    "        df=pd.DataFrame(df1)\n",
    "        \n",
    "        file_name = file_name[:-4]+'Lead II.csv'\n",
    "        output_file_path = os.path.join(output_path,file_name)\n",
    "        df.to_csv(output_file_path, index=False)\n",
    "        "
   ]
  },
  {
   "cell_type": "markdown",
   "id": "191f5748",
   "metadata": {},
   "source": [
    "Resampling multiple files iteratively"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "id": "4a35e1ba",
   "metadata": {},
   "outputs": [],
   "source": [
    "import seaborn as sns\n",
    "import matplotlib.pyplot as plt\n",
    "import pandas as pd\n",
    "import os\n",
    "import numpy as np\n",
    "from scipy.signal import resample\n",
    "\n",
    "#import xlrd # module for reading and writting excel files\n",
    "# creating empty dataframe for intializing and storing the value after each iteration\n",
    "folder_path = 'C:/Users/Ewunetie/OneDrive - University of Gondar,/2022-2023 files/Courses/Project/data/Online data/3 MIT-BIH Arrhythmia Database (Simple CSVs)'\n",
    "output_path = 'C:/Users/Ewunetie/OneDrive - University of Gondar,/2022-2023 files/Courses/Project/data/Online data/3 MIT-BIH Arrhythmia Database (Simple CSVs)/Resampled'\n",
    "files = os.listdir(folder_path)\n",
    "\n",
    "fs_original = 125  # Original sampling frequency (Hz)\n",
    "t_original = np.arange(0, 1.252, 1/fs_original)  # 16.384 seconds of data\n",
    "\n",
    "for file_name in files:\n",
    "    # Check if the file has a .mat extension\n",
    "    if file_name.endswith('.csv'):\n",
    "        # Construct the full path for the .mat file\n",
    "        csv_file_path = os.path.join(folder_path, file_name)        \n",
    "        # Load data from the .csv file\n",
    "        csv_data = pd.read_csv(csv_file_path)\n",
    "\n",
    "        # Define the new sampling frequency\n",
    "        fs_new = 125  # New sampling frequency (Hz)\n",
    "        # Resample the ECG signal to the new frequency\n",
    "        ecg_resampled = resample(csv_data, int(len(ecg_original) * fs_new / fs_original))\n",
    "        # Generate the time axis for the resampled signal\n",
    "        t_resampled = np.arange(0, 1.252, 1/fs_new)\n",
    "                \n",
    "        df=pd.DataFrame(ecg_resampled)\n",
    "        \n",
    "        file_name = file_name[:-4]+'.csv'\n",
    "        output_file_path = os.path.join(output_path,file_name)\n",
    "        df.to_csv(output_file_path, index=False)"
   ]
  }
 ],
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