title: How to merge columns from multiple CSV files using Python
body: <p>may be the answer of this question is available but I could not get proper solution and thus I am looking for the perfect solution. Suppose I have multiple CSV files (around 1500) having single column with some time series data (10,000 times or rows). The column header name is same in all CSV files. Suppose I have CSV files like:</p>
  
  <pre><code>aa1.csv      aa2.csv:      aa3.csv:............aa1500.csv:
  datavalue   datavalue      datavalue           datavalue
      4            1             1                  2
      2            3             6                  4
      3            3             3                  8                
      4            4             8                  9
  
  
  I want the output like this:
  
  
  datavalue,datavalue,datavalue,datavalue,.....datavalue
  4,1,1,..2
  2,3,6,..4
  3,3,3,..8
  4,4,8,..9
  </code></pre>
  
  <p>My codes are not working and giving something else:</p>
  
  <pre><code>import pandas as pd
  import csv
  import glob
  import os
  path 'F:/Work/'
  files_in_dir = [f for f in os.listdir(path) if f.endswith('csv')]
  for filenames in files_in_dir:
      df = pd.read_csv(filenames)
      df.to_csv('out.csv', mode='a')
  </code></pre>
  
  <p>If someone can help in this?</p>