Selenium Python my Xpath won't click the checkbox inside the table 1st column

I have a page with a table with some rows and columns. The first column has a checkbox (index is 0). The 2nd column has the name. There are some rows of data in the table. I would like to click the checkbox which has the name "Selenium_CRM_For_Edit_Test"

My XPATH won't click the checkbox. I can locate the checkbox using XPATH checker in Firebug. My XPATH is:

//table[@id="data_configuration_data_previews_ct_fields_body"]/tbody/tr//../td//../div/span[contains(text(), "Selenium_CRM_For_Edit_Test")]/preceding::div[1]//../input

The HTML is:

    <table id="data_configuration_data_previews_ct_fields_body" cellspacing="0" style="table-layout: fixed; width: 100%;">
<colgroup>
<tbody>
    <tr class="GJPPK2LBFG" __gwt_subrow="0" __gwt_row="0">
    <tr>.. some more rows here
    <tr class="GJPPK2LBEH" __gwt_subrow="0" __gwt_row="15">
    <tr class="GJPPK2LBFG" __gwt_subrow="0" __gwt_row="16">
<td class="GJPPK2LBEG GJPPK2LBGG GJPPK2LBHG">
    <div __gwt_cell="cell-gwt-uid-1417" style="outline-style:none;">
        <input type="checkbox" tabindex="-1"/>
    </div>
</td>
<td class="GJPPK2LBEG GJPPK2LBGG">
    <div __gwt_cell="cell-gwt-uid-1418" style="outline-style:none;">
        <span class="linkhover" title="MegaOne_CHROME" style="white-space:nowrap;overflow:hidden;text-overflow:ellipsis;empty-cells:show;display:block;color:#00A;cursor:pointer;">MegaOne_CHROME</span>
    </div>
</td>
    <td class="GJPPK2LBEG GJPPK2LBGG">
    <td class="GJPPK2LBEG GJPPK2LBGG">
    <td class="GJPPK2LBEG GJPPK2LBGG GJPPK2LBBH">
</tr>
<tr class="GJPPK2LBEH GJPPK2LBMG" __gwt_subrow="0" __gwt_row="17">
<td class="GJPPK2LBEG GJPPK2LBFH GJPPK2LBHG GJPPK2LBNG">
    <div __gwt_cell="cell-gwt-uid-1417" style="outline-style:none;">
        <input type="checkbox" tabindex="-1"/>
    </div>
</td>
<td class="GJPPK2LBEG GJPPK2LBFH GJPPK2LBNG">
    <div __gwt_cell="cell-gwt-uid-1418" style="outline-style:none;">
        <span class="linkhover" title="Selenium_CRM_Edit_Test" style="white-space:nowrap;overflow:hidden;text-overflow:ellipsis;empty-cells:show;display:block;color:#00A;cursor:pointer;">Selenium_CRM_Edit_Test</span>
    </div>
</td>
<td class="GJPPK2LBEG GJPPK2LBFH GJPPK2LBNG">
    <div __gwt_cell="cell-gwt-uid-1419" style="outline-style:none;">
        <span class="linkhover" title="view" style="white-space:nowrap;overflow:hidden;text-overflow:ellipsis;empty-cells:show;display:block;color:#00A;cursor:pointer;">view</span>
    </div>
</td>
<td class="GJPPK2LBEG GJPPK2LBFH GJPPK2LBNG">
<div __gwt_cell="cell-gwt-uid-1420" style="outline-style:none;">File</div>
</td>
<td class="GJPPK2LBEG GJPPK2LBFH GJPPK2LBBH GJPPK2LBNG">
    <div __gwt_cell="cell-gwt-uid-1421" style="outline-style:none;">498</div>
</td>
</tr>
<tr class="GJPPK2LBFG" __gwt_subrow="0" __gwt_row="18">
<tr class="GJPPK2LBEH" __gwt_subrow="0" __gwt_row="19">
<tr class="GJPPK2LBFG" __gwt_subrow="0" __gwt_row="20">
</tbody>
</table>

My Selenium Python code to select the checkbox is:

def select_a_data_preview(self, data_preview):
    # to get to the checkbox By.XPATH //table[@id="data_configuration_data_previews_ct_fields_body"]/tbody/tr//../td//../div/span[contains(text(), "Selenium_LADEMO_CRM_DONOTCHANGE")]/preceding::div[1]//../input
    data_preview_element = self.driver.find_element(By.XPATH, '//table[@id="data_configuration_data_previews_ct_fields_body"]/tbody/tr//../td//../div/span[contains(text(), "%s")]/preceding::div[1]//../input' % data_preview)
    data_preview_element.click()
    return self

I have also tried looping through the table, find the name from col 1 and then click col 0 which is where the checkbox is. It does not work. My code snippet is:

def select_a_data_preview(self, data_preview):
    try:
        WebDriverWait(self.driver, 20).until(EC.presence_of_element_located((By.ID, 'data_configuration_data_previews_ct_fields_body')))
        table_id = WebDriverWait(self.driver, 20).until(EC.presence_of_element_located((By.ID, 'data_configuration_data_previews_ct_fields_body')))
        rows = table_id.find_elements(By.TAG_NAME, "tr")
        for row in rows:
            # Get the columns
            col_checkbox = row.find_elements(By.TAG_NAME, "td")[0] # This ist the checkbox col
            col_name = row.find_elements(By.TAG_NAME, "td")[1]  # This is the Configuration Name column
            col_type = row.find_elements(By.TAG_NAME, "td")[3]  # This is the Type column
            col_rows = row.find_elements(By.TAG_NAME, "td")[4]  # This is the Rows column
            print "col_name.text = "
            print col_name.text
            print col_type.text
            print col_rows.text
            if (col_name.text == data_preview):
                col_checkbox.click()
                return True
        return False
    except NoSuchElementException, e:
        print "Element not found "
        print e
        self.save_screenshot("data_previews_page_select_element")
        return False
    return self

How can i click the checkbox that i want?

Thanks, Riaz