Python IN operator for List comparision

Question

I am working with Python plugins.
I have my list called station_list ,to which i had appended all the values.It contains all the integer values.
Now,I wanted to check my query result with list content. My code is:

self.db._exec_sql(c, "select distinct (station) from station  ")
for row in c.fetchall():
    for m in range(len_station_list):
        print row[0],station_list[m]

        if row[0] == station_list[m]:
                print 'true'

I am checking each selected row with list values. When i print and check, it gives correct answer.But comparision goes wrong.
It does not satisfy condition if row[0] == station_list[m]:.
What can be the problem?

Can you post the output from the print row[0],station_list[m] line, so we can see why the if fails? — Karl Barker
– Karl Barker, Commented Feb 27, 2012 at 8:31

NPatel · Accepted Answer · 2012-02-27 06:48:39Z

1

Try this.

x = self.db._exec_sql(c, "select distinct (station) from station  ").fetchall()

y = [p for p in x if p[0] in station_list]

answered Feb 27, 2012 at 6:48

NPatel

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3 Comments

user1111283 Over a year ago

Thanx for helping..p[0] checks for only one row.How to check for all rows?? and what does y contains??

glglgl Over a year ago

@user1111283 That's not true. p[0] checks for the first member (field) of each row. y contains all rows for which the first member is in your station_list - which should better be a set, not a list.

Karl Barker Over a year ago

@user1111283 the code in [ ] brackets is called a list comprehension - it will iterate through all the items in x and build a list containing all items in p where p[0] is in station_list.

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