extracting certain data from text file

[germ]

Hi I am new at python, so say I have a text folder with many number records in a single column how would I go about extracting only numbers that begin with zero and is either 10 or 7 digits long creating a new txt file for the 7 digit long numbers, the 10 digit long numbers and finally keeping the rest of the numbers in the original file?

Thanks in advance for your help!

[vegaseat]

What have you tried so far?

Hint, you can read the file in one line at a time using a for loop. Each line will be a string that can be processed using your criteria.

[germ]

this is what i got help!!!

input_file = open('xxx_extract.txt', 'rb')
for line in input_file:
if len(line.strip()) == 10
and line[0] == '0'
Strait_file.write(line)
elif len(line.strip()) == 7
and line[0] == '0'
Strait_7.write(line)

[Namibnat]

Here is how you can approach it:

create an empty list:

newVals = []

First of all deal with the file. Open the file, read it to a variable (The hint vegaseat gave you - in the file.readlines()) and then close the file, you have the contents already in 'line'

input_file = open('xxx_extract.txt', 'rb')
line = input_file.readlines()
input_file.close()

Now you do your searching through the file for the content you are looking for. That can usually be the headache, but in your case it's simple.

for l in line:
    if len(l.strip()) == 10 or len(l.strip()) == 7:
        if l[0] == '0':
            newVals.append(l.strip())

You can print to the console first until you are sure you have it working:

for i in newVals:
    print i

And then you can write to a new file with the same for loop as you used to print above. Just open the file with 'w' for right or 'a' for append.

[vegaseat]

Well, you were on the right track, but you have to make some modifications. Look at this example ...

# let's assume xxx_extract.txt is ...
"""\
1234567890
0123456789
1234567
0123456
0001234
01234567
0445566771
01234567890
"""

input_file = open('xxx_extract.txt', 'r')
# create new output files
out_file = open('new_extract.txt', 'w')
out7_file = open('7_extract.txt', 'w')
out10_file = open('10_extract.txt', 'w')

for line in input_file:
    # strip ending '\n'
    line = line.strip()
    if len(line) == 10 and line[0] == '0':
        # add '\n' back in
        out10_file.write(line + '\n')
    elif len(line) == 7 and line[0] == '0':
        out7_file.write(line + '\n')
    else:
        #print(line)  # test
        out_file.write(line + '\n')

print("file has been processed, check new files created")

Use a text editor to check the data in the files created.