title: Specifying data type in Pandas csv reader
body: <p>I am just getting started with Pandas and I am reading in a csv file using the <a href="http://pandas.pydata.org/pandas-docs/stable/generated/pandas.read_csv.html" rel="noreferrer"><code>read_csv()</code></a> method. The difficulty I am having is preventing pandas from converting my telephone numbers to large numbers, instead of keeping them as strings. I defined a converter which just left the numbers alone, but then they still converted to numbers. When I changed my converter to prepend a 'z' to the phone numbers, then they stayed strings. Is there some way to keep them strings without modifying the values of the fields?</p>