Change the comma delimiter in python output to csv

[kaf3773]

I am trying to output a list to a csv file and the line below work fine.

I need help with changing the delimiter from the default comma(,) to tab delimited.
csv_file = open('output.csv', 'w')
csv_writer = csv.writer(csv_file)

Help very much appreciated

Kaf

[Glenton]

This is done by setting a dialect in your csv writer. Dialect is an csv object and you can set the dialect.delimiter to '/t'.

See here

[kaf3773]

Thanks for the pointer Glenton. I got it to work by doing this
csv_writer = csv.writer(csv_file, delimiter="\t")

I am trying to use a date in an SQL where clause

prevday = datetime.date.today()-datetime.timedelta(1)
prev_day = prevday.strftime("%d-%b-%y")

and this is the SQL statement but it does not work

cur.execute("""select switch,percent_occupied from Table_name where switch =
('4DYHTE') and trunc(date_time) = %s""",("prev_day",))

I will appreciate any help

Thanks
Kaf

[Glenton]

Can you let us know what you mean by "does not work"? What's the error message? Does the prev_day need quotation marks?

[kaf3773]

Well i am trying to pass the data in the variable prev_day which is in this format dd-mon-yy to the SQL query.

without the quotes i get an invalid variable error

[dwblas]

prevday = datetime.date.today()-datetime.timedelta(1)

Print prevday to see what it contains. I don't think there is a default for timedelta so you have to specify one whatever, days=1, weeks=1, etc. From the docs

class datetime.timedelta([days[, seconds[, microseconds[, milliseconds[, minutes[, hours[, weeks]]]]]]])

[kaf3773]

Hello Glenton,

Sorry about this but i made a mistake about the error i was getting.

When i run it with or without the quotes this is the error message i get
Traceback (most recent call last):
File "spit.py", line 9, in <module>
('4DYHTE') and trunc(date_time) = %s""",("prev_day",))
cx_Oracle.DatabaseError: ORA-01036: illegal variable name/number

dwblas,

Concerning what is stored in prevday its the date for the previous day
>>> import datetime
>>> prevday = datetime.date.today()-datetime.timedelta(1)
>>> print prevday
2012-01-04
>>>
and i format it with this prev_day = prevday.strftime("%d-%b-%y")
to get
>>> prev_day = prevday.strftime("%d-%b-%y")
>>> print prev_day
04-Jan-12
>>>
which i want to pass to the SQL statement for the query.

Thanks for your help

[kaf3773]

i finally figured it out by doing this


cur.execute("""select switch,percent_occupied from Table_name where switch = '4DYHTE' and trunc(date_time) = ('%s')""" % (prev_day))

[bvdet]

Congratulations on solving your problem. Thanks for the feedback!