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PORead filenames from a textfile in python (double backslash issue)
 

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  1. PORead filenames from a textfile in python (double backslash issue)
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    <p>I am trying to read a list of files from a text file. I am using the following code to do that:</p> <pre><code>filelist = input("Please Enter the filelist: ") flist = open (os.path.normpath(filelist),"r") fname = [] for curline in flist: # check if its a coment - do comment parsing in this if block if curline.startswith('#'): continue fname.append(os.path.normpath(curline)); flist.close() #close the list file # read the slave files 100MB at a time to generate stokes vectors tmp = fname[0].rstrip() t = np.fromfile(tmp,dtype='float',count=100*1000) </code></pre> <p>This works perfectly fine and I get the following array:</p> <pre><code>'H:\\Shaunak\\TerraSAR_X- Sep2012-Glacier_Velocity_Gangotri\\NEST_oregistration\\Glacier_coreg_Cnv\\i_HH_mst_08Oct2012.bin\n' 'H:\\Shaunak\\TerraSAR_X- Sep2012-Glacier_Velocity_Gangotri\\NEST_oregistration\\Glacier_coreg_Cnv\\i_HH_mst_08Oct2012.bin\n' 'H:\\Shaunak\\TerraSAR_X- Sep2012-Glacier_Velocity_Gangotri\\NEST_oregistration\\Glacier_coreg_Cnv\\q_HH_slv3_08Oct2012.bin\n' 'H:\\Shaunak\\TerraSAR_X- Sep2012-Glacier_Velocity_Gangotri\\NEST_oregistration\\Glacier_coreg_Cnv\\q_VV_slv3_08Oct2012.bin' </code></pre> <p>The problem is that the <code>'\'</code> charecter is escaped and there is a trailing <code>'\n'</code> in the strings. I used the <code>str.rstrip()</code> to get rid of the '\n' - this works, but leaves the problem of the two back slashes.</p> <p>I have used the following approaches to try getting rid of these:</p> <ol> <li><p>Used the <code>codecs.unicode_escape_decode()</code> but I get this error: <code>UnicodeDecodeError: 'unicodeescape' codec can't decode bytes in position 56-57: malformed \N character escape</code>. Clearly this is not the right approach because I just want to decode the backslashed, not the rest of the string.</p></li> <li><p>This does not work either: <code>tmp = fname[0].rstrip().replace(r'\\','\\');</code></p></li> </ol> <p>Is there no way to make readline() read a raw string?</p> <hr> <p>UPDATE:</p> <p>Basically I have a text file with 4 file names I would like to open and read data from in python. The text file contains:</p> <pre><code>H:\Shaunak\TerraSAR_X-Sep2012-Glacier_Velocity_Gangotri\NEST_oregistration\Glacier_coreg_Cnv\i_HH_mst_08Oct2012.bin H:\Shaunak\TerraSAR_X-Sep2012-Glacier_Velocity_Gangotri\NEST_oregistration\Glacier_coreg_Cnv\i_HH_mst_08Oct2012.bin H:\Shaunak\TerraSAR_X-Sep2012-Glacier_Velocity_Gangotri\NEST_oregistration\Glacier_coreg_Cnv\q_HH_slv3_08Oct2012.bin H:\Shaunak\TerraSAR_X-Sep2012-Glacier_Velocity_Gangotri\NEST_oregistration\Glacier_coreg_Cnv\q_VV_slv3_08Oct2012.bin </code></pre> <p>I would like to open each file one by one and read 100MBs of data from them. When I use this command:<code>np.fromfile(flist[0],dtype='float',count=100)</code> I get this error:</p> <pre><code>Traceback (most recent call last): File "&lt;stdin&gt;", line 1, in &lt;module&gt; FileNotFoundError: [Errno 2] No such file or directory: 'H:\\Shaunak\\TerraSAR_X-Sep2012-Glacier_Velocity_Gangotri\\NEST_oregistration\\Glacier_coreg_Cnv\\i_HH_mst_08Oct2012.bin' </code></pre> <hr> <p>Update</p> <p>Full Traceback:</p> <pre><code>Please Enter the filelist: H:/Shaunak/TerraSAR_X- Sep2012-Glacier_Velocity_Gangotri/NEST_oregistration/Glacier_coreg_Cnv/filelist.txt Traceback (most recent call last): File "&lt;stdin&gt;", line 1, in &lt;module&gt; File "G:\WinPython-32bit-3.3.2.3\python-3.3.2\lib\site-packages\spyderlib\widgets\externalshell\sitecustomize.py", line 581, in runfile execfile(filename, namespace) File "G:\WinPython-32bit-3.3.2.3\python-3.3.2\lib\site-packages\spyderlib\widgets\externalshell\sitecustomize.py", line 41, in execfile exec(compile(open(filename).read(), filename, 'exec'), namespace) File "H:/Shaunak/Programs/Arnab_glacier_vel/Stokes_generation_2.py", line 28, in &lt;module&gt; t = np.fromfile(tmp,dtype='float',count=100*1000) FileNotFoundError: [Errno 2] No such file or directory: 'H:\\Shaunak\\TerraSAR_X-Sep2012-Glacier_Velocity_Gangotri\\NEST_oregistration\\Glacier_coreg_Cnv\\i_HH_mst_08Oct2012.bin' &gt;&gt;&gt; </code></pre>
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    1. USshaunakde
    1. USshaunakde
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    1. COWhat are you looking for, actually? Can you just provide what output would you like? It's a bit unclear for me.
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      1. PORead filenames from a textfile in python (double backslash issue)
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    2. CODouble slash is an internal representation; if you print the entry as an individual string, you'll see the regular single slash. You don't have to do anything with slashes.
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      1. PORead filenames from a textfile in python (double backslash issue)
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    3. CO@alKid Question updated. volcano - I am not able to use these string to read data : np.fromfile(tmp,dtype='float',count=100) Traceback (most recent call last): File "<stdin>", line 1, in <module> FileNotFoundError: [Errno 2] No such file or directory: 'H:\\Shaunak\\TerraSAR_X-Sep2012-Glacier_Velocity_Gangotri\\NEST_oregistration\\Glacier_coreg_Cnv\\i_HH_mst_08Oct2012.bin'
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      1. PORead filenames from a textfile in python (double backslash issue)
      1. USshaunakde
 

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