Adding stripped line to string/array in Python

Question

I am a fairly new programmer.

I am currently trying to find data from .txt files and add them to a string or array, which will then eventually be added to a .csv file.

The data I am looking at are currently present in this form, numerous times at random intervals within each .txt file:

' Line Flux: 3.0008e-19 +/- 2.6357e-21 [W/cm^2]'

Hence, after reading several ways around accessing this I have come up with a code that doesn't produce any errors, but doesn't print anything either:

cwd = os.getcwd()

def open_txt():
    flux = {}
    for file in cwd:
        if file.endswith('.txt'):
            f = open(file,'r')
            lines = f.readlines()
            for line in lines:
                if line.startswith(' Line Flux:'):
                    line.strip(' Line Flux:                        ' + '[W/cm^2]')
                    flux.append(line)
                    print flux

open_txt()

Is there anything glaringly obvious that I am doing incorrectly?

Thanks for reading. Any helpful replies would be greatly appreciated.

Answer 1

getcwd returns a string, so i think this is where your bug is. You are iterating through each letter of the string. Perhaps you need listdir.

You may want to check this link too.

---

If that is not the case you can try inserting the "print marker" and see if it opens a file at all

cwd = os.getcwd()

def open_txt():

    # This has to be a list, not a dict.
    flux = []
    for file in cwd:       

        if file.endswith('.txt'):
            # Check loop is entered, with this print marker
            print 'it opened file: %s'% file

            f = open(file,'r')
            lines = f.readlines()
            for line in lines:
                if line.startswith(' Line Flux:'):
                    line.strip(' Line Flux:                        ' + '[W/cm^2]')
                    flux.append(line)
                    print flux

open_txt()

---

Also, strip is removing all characters that you provided to it. Including / : e. strip('ab'+'cz') is equivalent to strip('acbz')

Instead you can use regular expressions:

import re

my_str = ' Line Flux: 3.0008e-19 +/- 2.6357e-21 [W/cm^2]'

pattern = re.compile(r'Line Flux: (.*?)\[W/cm\^2\]')
result = re.findall(pattern, my_str)

print result

Parenthesis in the pattern indicates which part of the match to be returned.