title: How to convert Object to Float in Python
body: <p>I have the following dataframe :</p>
  
  <pre><code>     Daily_KWH_System      year     month  day  hour  minute  second
   0         4136.900384      2016      9    7     0       0       0
   1         3061.657187      2016      9    8     0       0       0
   2         4099.614033      2016      9    9     0       0       0
   3         3922.490275      2016      9   10     0       0       0
   4         3957.128982      2016      9   11     0       0       0
   5         4177.014316      2016      9   12     0       0       0
   6         3077.103445      2016      9   13     0       0       0
   7         4123.103795      2016      9   14     0       0       0
  ..                ...       ...      ...  ...   ...     ...     ...
  551               NaN       2016      11  23     0       0       0
  552               NaN       2016      11  24     0       0       0
  553               NaN       2016      11  25     0       0       0
  ..                ...       ...      ...  ...   ...     ...     ...
  579               NaN       2016      11  27     0       0       0
  580               NaN       2016      11  28     0       0       0
  </code></pre>
  
  <p>The variables type is as follows: </p>
  
  <pre><code>print(df.dtypes)
  
  Daily_KWH_System    object
  year                 int32
  month                int32
  day                  int32
  hour                 int32
  minute               int32
  second               int32
  </code></pre>
  
  <p>I need to convert "Daily_KWH_System" to Float, so that I use in Linear Regression model.</p>
  
  <p>I tried the below code, which worked fine.</p>
  
  <pre><code> df['Daily_KWH_System'] = pd.to_numeric(df['Daily_KWH_System'], errors='coerce')
  </code></pre>
  
  <p>Then I replaced the NaN's to Blank space, to use in my model. And I used the following code</p>
  
  <pre><code> df = df.replace(np.nan,' ', regex=True)
  </code></pre>
  
  <p>But, again the variable " Daily_KWH_System" is getting converted to Object as soon as i replace NaN'. </p>
  
  <p>Please let me know how to go about it</p>