Python for loop question

Question

exepath = os.path.join(file location here)
exepath = '"' + os.path.normpath(exepath) + '"'

results = []

for e in ('90','52.62263','26.5651','10.8123'):
if e == '90':
    z = ('0',)
elif e == '52.62263':
    z = ('0', '72', '144', '216', '288')
elif e == '26.5651':
    z = (' 324', ' 36', ' 108', ' 180', ' 252')
else:
    z = (' 288', ' 0', ' 72', ' 144', ' 216')

for a in z:

    cmd = exepath + ' -e ' + str(e) + ' -a ' + str(a) + ' ' + sys.argv[1] + ' ' + sys.argv[2]
    print cmd
    process = Popen(cmd, shell=True, stderr=STDOUT, stdout=PIPE)

    outputstring = process.communicate()[0]
    outputlist = outputstring.splitlines()

    for i in outputlist:
        if i.find('The student says the area is:') != -1:
            print i
            results.append(i)
        print i

for s in results:
    print s

This is part of my code right now. It works perfectly fine. It scans the output of the exe file when fed through the numbers i give it in the for loop and spits out the line's that say The student says the area is 16 times for the group (90,0),(52.62263,0),...... etc. The only thing I want to fix is when it prints out the lines "The student says the area is", I want it just to print out for example (90,0) or whatever for whichever line it pertains to so it can be easily read. Any code would be helpful. I'm thinking about copying and pasting the for loop with the numbers and somehow calling it but not sure how. Thanks ahead of time. And of course i've imported everything correctly.

Right now it prints:

The Student says the area is: (" The Calculated number" ) ...x16 times

I just want the first line for example to print out:

The Student says the area is: (" The Calculated number" ) 90,0

doesn't have to be neat just the number printed out the side

the next one should be

The Student says the area is: (" The Calculated number") 52.62263,0

...x16

Answer 1

Since it's homework, I won't provide you with a straight-out answer, but I recommend you to have a look at the Python documentation for strings. Note the syntax for getting a slice of a string (aka substring), which is probably what you should be attempting.

Answer 2

I'm not completely sure I understand what question you're asking, but if you just want a line number from outputlist, you can keep your own counter:

idx = 0
for i in outputlist:
  if i.find('The student says the area is:') != -1:
    print idx, ": ", i
    results.append(i)
  idx += 1

And that should print something like:

15: The student says the area is 16 times for the group (90,0),(52.62263,0)

If that isn't what you want, perhaps you can clarify your question.

Answer 3

for e in ('90','52.62263','26.5651','10.8123'):
if e == '90':
    z = ('0',)
elif e == '52.62263':
    z = ('0', '72', '144', '216', '288')
elif e == '26.5651':
    z = (' 324', ' 36', ' 108', ' 180', ' 252')
else:
    z = (' 288', ' 0', ' 72', ' 144', ' 216')

Hmm. I think you want to look at the section in the Python tutorials about dictionaries.

Answer 4

If all you need is the number printed out:

print '%s %s, %s' % (i, e, a)

This assumes that e and a are the numbers you want (or that's what I can tell based on a quick read).

Answer 5

Note: A big part of writing python is to make your code readable, so in the future you might try using more descriptive variable names. PEP8 is the go-to solution for formatting python.

Another note: Questions that are asked clearly and concisely tend to get a better response from the Stack Overflow community. The less we have to work to understand you, the faster and more accurate we are in our response.

Resources:

1. Dictionaries
2. String formatting operations
3. "in" keyword

Since you are adamant about the question not being homework, here is a cleaner version of your code with what I think you were asking added in.

Code:

import os
from os import popen

exepath = os.path.join(file location here)
exepath = '"' + os.path.normpath(exepath) + '"'

# This format is a little cleaner than the if-else statement.
# A dictionary (key=e, value=z) that holds your data.
data = {
        '90': ('0',),
        '52.62263': ('0', '72', '144', '216', '288'),
        '26.5651': (' 324', ' 36', ' 108', ' 180', ' 252'),
        '10.8123': (' 288', ' 0', ' 72', ' 144', ' 216'),
       }

results = []

# This is how you loop over (key, value) pairs in a dictionary
for e, z in data.iteritems():

    for a in z:
        cmd = ' '.join([exepath, '-e', str(e), '-a', str(a), sys.argv[1], sys.argv[2]])
        #or you could use the following (string substitution):
        #cmd = '%s -e %s -a %s %s %s' % (exepath, e, a, sys.argv[1], sys.argv[2])
        print cmd
        process = popen(cmd, shell=True, stderr=STDOUT, stdout=PIPE)

        output_list = process.communicate()[0].splitlines()

        for output in output_list:
            # the "in" keyword is more readable
            if 'The student says the area is:' in output:

                # this is, I believe, the line you were asking about...
                # should look like:
                # "The Student says the area is: ("The Calculated number") 90,0"
                formatted_output = '%s %s,%s' % (output, e, a)

                print formatted_output
                results.append(formatted_output)
            print output

for student_answer in results:
    print student_answer