Is there a way to append pandas dataframe at once

Is there a way to append all pandas dataframe at once. For example, I have below

df['A'] 
col1  col2
 1     x
 2     y

df['B'] 
col1  col2
 1     x5
 2     y2

df['F'] 
col1  col2
 13    x3
 2     y3
.
.
.
.
.
df['H']
col1  col2
 13    x1
 23    y2

I have many dataframe with same columns and with different variable name. Is there a way to append this along with variable name in the columns

Expected output

File  col1    col2 
 A     1       x
 A     2       y
 B     1       x5
 B     2       y2
 F     13      x3
 F     2       y3
 .     .       .
 .     .       .
 H     13      x1
 H     23      y2

>Solution :

You can use pd.concat

>>> import pandas as pd
>>> A = pd.DataFrame({"col1": [1, 2], "col2":["x","y"]})
>>> B = pd.DataFrame({"col1": [1, 2], "col2": ["x5", "y2"]})
>>> A["File"] = "A"
>>> B["File"] = "B"
>>> pd.concat([A,B])
   col1 col2 File
0     1    x    A
1     2    y    A
0     1   x5    B
1     2   y2    B

For multiple dfs, one can use

dfs = []
for file_col in file_cols:
    newdf = df[file_col]
    newdf["File"] = file_col
    dfs.append(newdf)
pd.concat(dfs)