Pandas create empty DataFrame with only column names

Question

I have a dynamic DataFrame which works fine  but when there are no data to be added into the DataFrame I get an error  And therefore I need a solution to create an empty DataFrame with only the column names   For now I have something like this   df   pd DataFrame columns COLUMN NAMES    Note that there are now row data inserted    PS  It is important that the column names would still appear in a DataFrame   But when I use it like this I get something like that as a result   Index     dtype  object   Empty DataFrame   The  Empty DataFrame  part is good  But instead of the Index thing I need to still display the columns   Edit   An important thing that I found out  I am converting this DataFrame to a PDF using Jinja2  so therefore I m calling out a method to first output it to HTML like that   df to html     This is where the columns get lost I think   Edit2  In general  I followed this example  http   pbpython com pdf-reports html  The css is also from the link  That s what I do to send the dataframe to the PDF   env   Environment loader FileSystemLoader       template   env get template  pdf report template html   template vars     my dataframe   df to html     html out   template render template vars  HTML string html out  write pdf  my pdf pdf   stylesheets   pdf report style css      Edit3   If I print out the dataframe right after creation I get the followin    0 rows x 9 columns  Empty DataFrame Columns   column a  column b  column c  column d   column e  column f  column g   column h  column i  Index       That seems reasonable  but if I print out the template vars    my dataframe     lt table border  1  class  dataframe  gt  n   lt tbody gt  n     lt tr gt  n       lt td gt Index     dtype   object    lt  td gt  n       lt td gt Empty DataFrame lt  td gt  n     lt  tr gt  n   lt  tbody gt  n lt  table gt     And it seems that the columns are missing already   E4  If I print out the following   print df to html      I get the following result already    lt table border  1  class  dataframe  gt     lt tbody gt       lt tr gt         lt td gt Index     dtype  object   lt  td gt         lt td gt Empty DataFrame lt  td gt       lt  tr gt     lt  tbody gt   lt  table gt

User · Accepted Answer

You can create an empty DataFrame with either column names or an Index:

In [4]: import pandas as pd
In [5]: df = pd.DataFrame(columns=['A','B','C','D','E','F','G'])
In [6]: df
Out[6]:
Empty DataFrame
Columns: [A, B, C, D, E, F, G]
Index: []

Or

In [7]: df = pd.DataFrame(index=range(1,10))
In [8]: df
Out[8]:
Empty DataFrame
Columns: []
Index: [1, 2, 3, 4, 5, 6, 7, 8, 9]

Edit: Even after your amendment with the .to_html, I can't reproduce. This:

df = pd.DataFrame(columns=['A','B','C','D','E','F','G'])
df.to_html('test.html')

Produces:

<table border="1" class="dataframe">
  <thead>
    <tr style="text-align: right;">
      <th></th>
      <th>A</th>
      <th>B</th>
      <th>C</th>
      <th>D</th>
      <th>E</th>
      <th>F</th>
      <th>G</th>
    </tr>
  </thead>
  <tbody>
  </tbody>
</table>

User · Answer

Creating colnames with iterating df   pd DataFrame columns   colname     str i  for i in range 5    print df     Empty DataFrame   Columns   colname 0  colname 1  colname 2  colname 3  colname 4    Index      to html   operations print df to html        lt table border  quot 1 quot  class  quot dataframe quot  gt       lt thead gt         lt tr style  quot text-align  right  quot  gt           lt th gt  lt  th gt           lt th gt colname 0 lt  th gt           lt th gt colname 1 lt  th gt           lt th gt colname 2 lt  th gt           lt th gt colname 3 lt  th gt           lt th gt colname 4 lt  th gt         lt  tr gt       lt  thead gt       lt tbody gt       lt  tbody gt     lt  table gt   this seems working print type df to html        lt class  str  gt   The problem is caused by when you create df like this df   pd DataFrame columns COLUMN NAMES   it has 0 rows    n columns  you need to create at least one row index by df   pd DataFrame columns COLUMN NAMES  index  0    now it has 1 rows    n columns  You are be able to add data  Otherwise its df that only consist  colnames  object like a string list

User · Answer

Are you looking for something like this       COLUMN NAMES   A   B   C   D   E   F   G       df   pd DataFrame columns COLUMN NAMES      df columns     Index   A    B    C    D    E    F    G    dtype  object

User · Answer

df to html   has a columns parameter   Just pass the columns into the to html   method   df to html columns   A   B   C   D   E   F   G

[python] Pandas create empty DataFrame with only column names

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