title: Unable to convert dataframe to parquet, TypeError
body: <p>I was trying to convert a data frame to a parquet file. But I faced the following error.</p>
  <pre><code>result = pa.array(col, type=type_, from_pandas=True, safe=safe)
    File &quot;pyarrow\array.pxi&quot;, line 265, in pyarrow.lib.array
    File &quot;pyarrow\array.pxi&quot;, line 80, in pyarrow.lib._ndarray_to_array
    File &quot;pyarrow\error.pxi&quot;, line 107, in pyarrow.lib.check_status
  pyarrow.lib.ArrowTypeError: ('Expected a string or bytes dtype, got float64', 'Conversion failed for column NOTES with type float64')
  </code></pre>
  <p>The column type is varchar, so this it converts to str. But there are a few numeric values in the records of that column, and I am doubtful that the data frame parses them as float. Thus, while converting to parquet, it returns a float value that produces an error.</p>
  <p>Is there a way to convert the values of these records to str format.</p>
  <blockquote>
  <p>I tried using astype(str) but didn't work.</p>
  </blockquote>