Python: For loop problem

Question

I have a simple for loop problem, when i run the code below it prints out series of 'blue green' sequences then a series of 'green' sequences. I want the output to be; if row[4] is equal to 1 to print blue else print green.

 for row in rows:
        for i in `row[4]`:
            if i ==`1`:
                print 'blue '
            else:
                print 'green '

Any help would be grateful

thanks

Yas

that doesn't seem like a valid python code. also, what is rows? — SilentGhost
– SilentGhost, Commented Mar 11, 2010 at 16:31
do you mean the contents of row at index 4 ( the fifth element ) is == 1 print blue else print green, or do you want to print blue on every forth line else print green? — user177800
– user177800, Commented Mar 11, 2010 at 16:33
I don't think you're using the backticks correctly (do you really want the repr of row[4]?). Is that a literal cut and paste of your code or did you edit it? — Daniel Pryden
– Daniel Pryden, Commented Mar 11, 2010 at 17:00

unwind · Accepted Answer · 2010-03-11 16:34:01Z

3

Try something like this:

for i in xrange(len(rows)):
  if rows[i] == '1':
    print "blue"
  else:
    print "green"

Or, since you don't actually seem to care about the index, you can of course do it more cleanly:

for r in rows:
  if r == "1":
    print "blue"
  else:
    print "green"

edited Mar 11, 2010 at 16:34

answered Mar 11, 2010 at 16:28

unwind

402k64 gold badges492 silver badges620 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

LB40 Over a year ago

why not doing for row in rows and testing the value of row ?

unwind Over a year ago

@LB: Um ... Because I was being a bit literal-minded, I guess. It happens. I'll edit, thanks!

score 2 · Accepted Answer · 2010-03-11 17:32:17Z

2

the enumerate() function will iterate and give you the index as well as the value:

for i, v in enumerate(rows):
    if i == 4:
        print "blue"
    else:
        print "green"

if you want to print blue on every fourth line else green do this:

for i, v in enumerate(rows):
    if i % 4 == 0:
        print "blue"
    else:
        print "green"

edited Mar 11, 2010 at 17:32

answered Mar 11, 2010 at 16:31

user177800

Comments

Thiago Chaves · Accepted Answer · 2010-03-11 16:30:16Z

1

if rows[4] == 1:
    print 'blue'
else:
    print 'green'

answered Mar 11, 2010 at 16:30

Thiago Chaves

9,5235 gold badges32 silver badges25 bronze badges

Collectives™ on Stack Overflow

Python: For loop problem

3 Answers 3

2 Comments

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

2 Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related