Python Find Forward Slash in a String

Question

I am a beginner to Python so bear with me. Basically I am searching a particular table cell for the forward slash character. If the cell contains that character, I want to delete the entire row.

counter = 0
for row in table:
    if row[7].find("/") != -1:
        del table[counter]
        continue
    counter+=1

The code above never detects the forward slash but finds any other character I substitute for forward slash. Any help would be much appreciated.

Why the index 7? Use the syntax "/" in row[7], it's much more Pythonic. You should really avoid deleting elements of the list you're iterating over as that causes undefined behaviour. You can also use for counter, row in enumerate(table): and avoid having to keep your own counter variable. — moinudin
– moinudin, Commented Dec 10, 2010 at 17:10
@marcog: Unfortunately enumerate() can't help in this case. — Ignacio Vazquez-Abrams
– Ignacio Vazquez-Abrams, Commented Dec 10, 2010 at 17:23

Ignacio Vazquez-Abrams · Accepted Answer · 2010-12-10 17:05:50Z

4

There's so many things wrong with that code it's easier to just re-write it.

table[:] = [row for row in table if '/' not in row[7]]

answered Dec 10, 2010 at 17:05

Ignacio Vazquez-Abrams

804k160 gold badges1.4k silver badges1.4k bronze badges

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

4 Comments

pafcu Over a year ago

If you take the time to answer you might as well take the time to explain what was wrong in the original code

Tyler Durden Over a year ago

Thanks, this worked perfectly. Like I said, I am a beginner and am just picking up on all the syntax.

Ignacio Vazquez-Abrams Over a year ago

@Tyler: The biggest thing to remember is to never modify a sequence you're iterating over.

Tyler Durden Over a year ago

Another quick question regarding this and I promise to leave you alone. Using the same format as above, how would I delete the row if the element in row[7] wasn't between the numbers 1 to 10.

Iacks · Accepted Answer · 2010-12-10 17:20:21Z

-2

Could you not just maybe do..

for row in table:
    if '/' in row[7]:
        row.delete()

Or if you really need the counter to del the row from the table, then just put the counter back in.

edited Dec 10, 2010 at 17:20

answered Dec 10, 2010 at 17:09

Iacks

3,8552 gold badges23 silver badges24 bronze badges

7 Comments

Ignacio Vazquez-Abrams Over a year ago

This code will do nothing. The name row is defined by the loop and not a reference to anything in table.

Iacks Over a year ago

This code should work fine, I cannot see what your are saying.

Ignacio Vazquez-Abrams Over a year ago

del deletes names, not objects. That objects may be deleted by executing it is incidental.

user395760 Over a year ago

-1 It's wrong as Ignacio states. Try it out: xs = range(N); for x in xs: del x leaves xs untouched.

Iacks Over a year ago

I wasnt fully trying to write code i just snapped it out without thinking what del means in python.

|

Collectives™ on Stack Overflow

Python Find Forward Slash in a String

2 Answers 2

4 Comments

7 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

4 Comments

7 Comments

Your Answer

Sign up or log in

Post as a guest

Related