pandas_to_html_flask.py

'''
Description:
    Using pandas display 200 lines of csv at a time. Csv for example could be an import from a database.
'''

"""
If you plan to test this with a sample csv then you may use the following code to generate csv:

file = open("large.csv", "w")

count = 0

file.write("Index , col1, col2, col3, col4, col5, col6, col7, col8\n")
for x in range(1,10000):
    file.write(str(x) + ", col1-" + str(x) + ", col2-" + str(x) +  ", col3-" + str(x) + ", col4-" + str(x) + ", col5-" + str(x) + ", col6-" + str(x) + ", col7-" + str(x) + ", col8-" + str(x) + "\n")

file.close()
""


__author__ = 'Sujayyendhiren Srinivasamurthi'
__email__ = 'sujayy1983@gmail.com'

@app.route("/read")
@app.route("/read/<pgNum>")
def read_data(pgNum=None):
    df = pd.read_csv('large.csv')

    #Excluding one row that is table header
    totalRows = len(df.index) -1
    minPgNum = 0
    maxPgNum = 0

    line = """<a href="http://%s:5000/read/%s">%s</a> &nbsp &nbsp &nbsp &nbsp"""
    template = """<ul class="pagination"> %s </ul>"""

    if(pgNum == None):
        pgNum = 1
        minPgNum = 0

        if totalRows > 200:
            maxPgNum = 200
        else:
            maxPgNum = totalRows
    else:
        pgNum = int(pgNum)-1
        if pgNum*200 >= 0 and ((pgNum+1)*200)+1 <= totalRows:
            minPgNum = pgNum * 200
            maxPgNum = (pgNum+1)* 200
        else:
            pgNum = 0
            minPgNum = 0
            maxPgNum = 200

    buildLines = line %('192.168.0.6', pgNum , 'prev') + line %('192.168.0.6', pgNum+2 , 'next')
    return template %(buildLines) + "<br>" + df[ minPgNum:maxPgNum].to_html(index=False)