Run only if "if " statement is true.! - python

So I've a question, Like I'm reading the fits file and then i'm using the information from the header of the fits to define the other files which are related to the original fits file. But for some of the fits file, the other files (blaze_file, bis_file, ccf_table) are not available. And because of that my code gives the pretty obvious error that No Such file or directory.
import pandas as pd
import sys, os
import numpy as np
from glob import glob
from astropy.io import fits
PATH = os.path.join("home", "Desktop", "2d_spectra")
for filename in os.listdir(PATH):
if filename.endswith("_e2ds_A.fits"):
e2ds_hdu = fits.open(filename)
e2ds_header = e2ds_hdu[0].header
date = e2ds_header['DATE-OBS']
date2 = date = date[0:19]
blaze_file = e2ds_header['HIERARCH ESO DRS BLAZE FILE']
bis_file = glob('HARPS.' + date2 + '*_bis_G2_A.fits')
ccf_table = glob('HARPS.' + date2 + '*_ccf_G2_A.tbl')
if not all(file in os.listdir(PATH) for file in [blaze_file,bis_file,ccf_table]):
continue
So what i want to do is like, i want to make my code run only if all the files are available otherwise don't. But the problem is that, i'm defining the other files as variable inside the for loop as i'm using the header information. So how can i define them before the for loop???? and then use something like
So can anyone help me out of this?

The filenames returned by os.listdir() are always relative to the path given there.
In order to be used, they have to be joined with this path.
Example:
PATH = os.path.join("home", "Desktop", "2d_spectra")
for filename in os.listdir(PATH):
if filename.endswith("_e2ds_A.fits"):
filepath = os.path.join(PATH, filename)
e2ds_hdu = fits.open(filepath)
…
Let the filenames be ['a', 'b', 'a_ed2ds_A.fits', 'b_ed2ds_A.fits']. The code now excludes the two first names and then prepends the file path to the remaining two.
a_ed2ds_A.fits becomes /home/Desktop/2d_spectra/a_ed2ds_A.fits and
b_ed2ds_A.fits becomes /home/Desktop/2d_spectra/b_ed2ds_A.fits.
Now they can be accessed from everywhere, not just from the given file path.
I should become accustomed to reading a question in full before trying to answer it.
The problem I mentionned is a problem if you don't start the script from any path outside the said directory. Nevertheless, applying it will make your code much more consistent.
Your real problem, however, lies somewhere else: you examine a file and then, after checking its contents, want to read files whose names depend on informations from that first file.
There are several ways to accomplish your goal:
Just extend your loop with the proper tests.
Pseudo code:
for file in files:
if file.endswith("fits"):
open file
read date from header
create file names depending on date
if all files exist:
proceed
or
for file in files:
if file.endswith("fits"):
open file
read date from header
create file names depending on date
if not all files exist:
continue # actual keyword, no pseudo code!
proceed
Put some functionality into functions (variation of 1.)
Create a loop in a generator function which yields the "interesting information" of one fits file (or alternatively nothing) and have another loop run over them to actually work with the data.
If I am still missing some points or am not detailled enough, please let me know.

Since you have to read the fits file to know the other dependant files names, there's no way you can avoid reading the fit file first. The only thing you can do is test for the dependant files existance before trying to read them and skip the rest of the loop (using continue) if not.

Edit this line
e2ds_hdu = fits.open(filename)
And replace with
e2ds_hdu = fits.open(os.path.join(PATH, filename))

Related

Changing filenames in folders

I have a folder that contains a lot of files that has a lot of copies which make them unreadable.
Example:
cow.txt
cow.txt(1)
cow.txt(2)
cow.txt(3)
dog.txt
dog.txt(1)
I would like to to have all the files structured in away that makes them able to be opened. Example
cow.txt
cow(1).txt
cow(2).txt
cow(3).txt
dog.txt
dog(1).txt
Any help you can provided would be greatly appreciated. I am just looking to make sure there name is changed, and am not looking to read each individual file. In addition if possible I would like to break up the files into 20k blocks. Thank you in advance.
I have tried using os.rename to simply rename the file but I am confused on how to do the efficiently as the numbers come after the .txt I then decided to read all the files and convert them to a pandas data frame and fix it that way. However I am confused on how to pull the files and make them with that name.
list_of_files = os.listdir()
df = pd.DataFrame(list_of_files, columns = ['File_Name'])
df['.txt_removed'] = df.replace(to_replace = '.txt', value = '', regex = True)
df['txt_add'] = df['.txt_removed'] + '.txt'
To pull the files I would do something like this
for filewant_in df['txt_add']:
if filewant in os.listdir():
sutil.copy(os.path.join(filewant), 'new location')
I do not think this option will work even though it gives me my intended result. As I would like to change the overall file names.
You can use python's standard library, the os module has the os.rename function.
Like this:
It works like this:
os.rename('cow.txt(1)', 'cow(1).txt')
Create a .py file and paste the code below then run it. Change /mydir path with the path to the directory having the files. The code will loop through the directory finding all the containing have .txt as part of the file extension and renaming them to a .txt file. I hope it works.
import glob, os
os.chdir("/mydir")
for file in glob.glob("*.txt*"):
file_name = os.path.basename(file)
part_name = file_name.split(".", 1)
new_name = part_name[0]+'.txt'
os.rename(file,new_name)

Write Path Names to a File (Python)

I'm dealing with a large number of images and am trying to conduct a search for jpegs and then write their paths to a file.
Currently, I can find all the jpegs I want. However, each new path in my 'index' file overwrites the last. Consequently, it's not an index/list at all, but a text file containing a/path/to/just/one/file.jpg
I've simplified my code and added it below. It's verbose but that's for my reading benefit as well as for others who are new like myself.
#----------
#-->Import Modules
#I'm pretty sure there is redundancy here and it's not well laid out
#but I'm new to coding and it works
import os
import pathlib
import glob, os
from pathlib import Path
import os.path
from os import path
#----------
#-->Global Vars
#Simplified example of my variables
working_dir = "/Users/myname/path/to/working dir"
records_dir = str(working_dir + "/Records")
#----------
#-->Search Location
#Define where the jpeg search is to take place
#(actually dictated via user input, Minecraft is just an example)
search_locations = ["/Users/myname/minecraft"]
#---------
#--> Search for jpgs and write their paths to a file
#define the file where the jpeg paths are to be stored,
#(I'm referring to the storage file as an index of sorts)
jpg_index = str(records_dir + "/index_for_all_jpgs")
#Its embedded in a forloop because the user can add multiple locations
for search_location in search_locations:
#get the desired paths from the search location
for path in Path(search_location).rglob('*.jpg'):
#Open the index where paths are to be stored
with open(jpg_index, 'w') as filehandle:
#This is supposed to write each paths as a new line
#But it doesn't work
filehandle.writelines('%s\n' % path)
I have also tried using a simpler idea;
filehandle.write(path)
and a more complex one that I don't fully understand;
filehandle.writelines("%s\n" % path for path in search_location)
Yet all I have done is failed in a slightly different way.
The 'w' option tells the open() method to overwrite anything previously in the jpg_index file. Because you call this method each time before you write a jpeg path to it, only the last one remains. Use 'a' (append) in place of 'w' (write) to tell the open() method to append to the file instead of overwriting it each time.
For instance:
for search_location in search_locations:
for path in Path(search_location).rglob('*.jpg'):
with open(jpg_index, 'a') as filehandle:
filehandle.writelines('%s\n' % path)
Alternatively, you could move the with... as statement outside of the for loops. This way, the jpg_index file will only be opened and overwritten once at the beginning and not after there is already information in it.
For example:
with open(jpg_index, 'w') as filehandle:
for search_location in search_locations:
for path in Path(search_location).rglob('*.jpg'):
filehandle.writelines('%s\n' % path)

How to load data set having multiple 'No-extension files' in python?

I am trying to load a dataset for my machine learning project and it requires me to load files having no extensions.
I tried :
import os
import glob
files = filter(os.path.isfile, glob.glob("./[0-9]*"))
for name in files:
with open(name) as fh:
contents = fh.read()
But doesn't return anything, mainly that glob command has nothing in it.
Also tried :
import os
import glob
path = './dataset1/training_validation/2012-07-10/'
for infile in glob.glob(os.path.join(path, '*')):
print("test")
file = open(infile, 'r')
print(file)
but this returns [] because of that glob command.
I'm stuck in here and couldn't find anything over the internet.
My actual problem is to load 'no extension files in a training and testing set' from two folders, validation, and the test itself. I can iterate through the folder but don't know how to handle those file types.
When I open those files in a text editor. it shows me something like this.
So I know that it's a binary format of an image, but have no idea how can I store and train them.
any help would be appreciated. thanks.
Two things:
File extensions (.txt , .dat , .bat, .f90, etc.) are not meaningful to python, at least when using glob or numpy or something of the sort, because it's just part of a string. Some of us are raised (within Windows) to believe that file extensions mean something (I too fell for it).
The file you are looking at is a text file, containing the ASCII representation of a binary image on 0's and 1's. So, it's not a binary file, and it's not an image file (per-se), but it is a text file, which means we can read it as such from python.
To read this in, you could do either:
1. Use numpy to do data = numpy.loadtxt(<filename>), however you might have trouble delimiting the digits.
2. Use Python's standard open function on the file, and loop through each line using for line in <file_handle>:. This way, each row of data is a string, which can be parsed easily (see documentation on string indexing).
Good luck!
IMO this simply means that your path does not exist.
Perhaps you try in a first test an absolute path to your folder, as you eventually confused the relative position of the folder to your current working directory.
I got it to work with the following code.
fileNames = [f for f in listdir(dirName) if isfile(join(dirName, f))]
random.shuffle(fileNames)
for files in fileNames:
data = open(dirName+'/'+files,'r');
Thanks for your responses.

taking data from files which are in folder

How do I get the data from multiple txt files that placed in a specific folder. I started with this could not fix. It gives an error like 'No such file or directory: '.idea' (??)
(Let's say I have an A folder and in that, there are x.txt, y.txt, z.txt and so on. I am trying to get and print the information from all the files x,y,z)
def find_get(folder):
for file in os.listdir(folder):
f = open(file, 'r')
for data in open(file, 'r'):
print data
find_get('filex')
Thanks.
If you just want to print each line:
import glob
import os
def find_get(path):
for f in glob.glob(os.path.join(path,"*.txt")):
with open(os.path.join(path, f)) as data:
for line in data:
print(line)
glob will find only your .txt files in the specified path.
Your error comes from not joining the path to the filename, unless the file was in the same directory you were running the code from python would not be able to find the file without the full path. Another issue is you seem to have a directory .idea which would also give you an error when trying to open it as a file. This also presumes you actually have permissions to read the files in the directory.
If your files were larger I would avoid reading all into memory and/or storing the full content.
First of all make sure you add the folder name to the file name, so you can find the file relative to where the script is executed.
To do so you want to use os.path.join, which as it's name suggests - joins paths. So, using a generator:
def find_get(folder):
for filename in os.listdir(folder):
relative_file_path = os.path.join(folder, filename)
with open(relative_file_path) as f:
# read() gives the entire data from the file
yield f.read()
# this consumes the generator to a list
files_data = list(find_get('filex'))
See what we got in the list that consumed the generator:
print files_data
It may be more convenient to produce tuples which can be used to construct a dict:
def find_get(folder):
for filename in os.listdir(folder):
relative_file_path = os.path.join(folder, filename)
with open(relative_file_path) as f:
# read() gives the entire data from the file
yield (relative_file_path, f.read(), )
# this consumes the generator to a list
files_data = dict(find_get('filex'))
You will now have a mapping from the file's name to it's content.
Also, take a look at the answer by #Padraic Cunningham . He brought up the glob module which is suitable in this case.
The error you're facing is simple: listdir returns filenames, not full pathnames. To turn them into pathnames you can access from your current working directory, you have to join them to the directory path:
for filename in os.listdir(directory):
pathname = os.path.join(directory, filename)
with open(pathname) as f:
# do stuff
So, in your case, there's a file named .idea in the folder directory, but you're trying to open a file named .idea in the current working directory, and there is no such file.
There are at least four other potential problems with your code that you also need to think about and possibly fix after this one:
You don't handle errors. There are many very common reasons you may not be able to open and read a file--it may be a directory, you may not have read access, it may be exclusively locked, it may have been moved since your listdir, etc. And those aren't logic errors in your code or user errors in specifying the wrong directory, they're part of the normal flow of events, so your code should handle them, not just die. Which means you need a try statement.
You don't do anything with the files but print out every line. Basically, this is like running cat folder/* from the shell. Is that what you want? If not, you have to figure out what you want and write the corresponding code.
You open the same file twice in a row, without closing in between. At best this is wasteful, at worst it will mean your code doesn't run on any system where opens are exclusive by default. (Are there such systems? Unless you know the answer to that is "no", you should assume there are.)
You don't close your files. Sure, the garbage collector will get to them eventually--and if you're using CPython and know how it works, you can even prove the maximum number of open file handles that your code can accumulate is fixed and pretty small. But why rely on that? Just use a with statement, or call close.
However, none of those problems are related to your current error. So, while you have to fix them too, don't expect fixing one of them to make the first problem go away.
Full variant:
import os
def find_get(path):
files = {}
for file in os.listdir(path):
if os.path.isfile(os.path.join(path,file)):
with open(os.path.join(path,file), "r") as data:
files[file] = data.read()
return files
print(find_get("filex"))
Output:
{'1.txt': 'dsad', '2.txt': 'fsdfs'}
After the you could generate one file from that content, etc.
Key-thing:
os.listdir return a list of files without full path, so you need to concatenate initial path with fount item to operate.
there could be ideally used dicts :)
os.listdir return files and folders, so you need to check if list item is really file
You should check if the file is actually file and not a folder, since you can't open folders for reading. Also, you can't just open a relative path file, since it is under a folder, so you should get the correct path with os.path.join. Check below:
import os
def find_get(folder):
for file in os.listdir(folder):
if not os.path.isfile(file):
continue # skip other directories
f = open(os.path.join(folder, file), 'r')
for line in f:
print line

Changing name of file until it is unique

I have a script that downloads files (pdfs, docs, etc) from a predetermined list of web pages. I want to edit my script to alter the names of files with a trailing _x if the file name already exists, since it's possible files from different pages will share the same filename but contain different contents, and urlretrieve() appears to automatically overwrite existing files.
So far, I have:
urlfile = 'https://www.foo.com/foo/foo/foo.pdf'
filename = urlfile.split('/')[-1]
filename = foo.pdf
if os.path.exists(filename):
filename = filename('.')[0] + '_' + 1
That works fine for one occurrence, but it looks like after one foo_1.pdf it will start saving as foo_1_1.pdf, and so on. I would like to save the files as foo_1.pdf, foo_2.pdf, and so on.
Can anybody point me in the right direction on how to I can ensure that file names are stored in the correct fashion as the script runs?
Thanks.
So what you want is something like this:
curName = "foo_0.pdf"
while os.path.exists(curName):
num = int(curName.split('.')[0].split('_')[1])
curName = "foo_{}.pdf".format(str(num+1))
Here's the general scheme:
Assume you start from the first file name (foo_0.pdf)
Check if that name is taken
If it is, iterate the name by 1
Continue looping until you find a name that isn't taken
One alternative: Generate a list of file numbers that are in use, and update it as needed. If it's sorted you can say name = "foo_{}.pdf".format(flist[-1]+1). This has the advantage that you don't have to run through all the files every time (as the above solution does). However, you need to keep the list of numbers in memory. Additionally, this will not fill any gaps in the numbers
Why not just use the tempfile module:
fileobj = tempfile.NamedTemporaryFile(suffix='.pdf', prefix='', delete = False)
Now your filename will be available in fileobj.name and you can manipulate to your heart's content. As an added benefit, this is cross-platform.
Since you're dealing with multiple pages, this seeems more like a "global archive" than a per-page archive. For a per-page archive, I would go with the answer from #wnnmaw
For a global archive, I would take a different approch...
Create a directory for each filename
Store the file in the directory as "1" + extension
write the current "number" to the directory as "_files.txt"
additional files are written as 2,3,4,etc and increment the value in _files.txt
The benefits of this:
The directory is the original filename. If you keep turning "Example-1.pdf" into "Example-2.pdf" you run into a possibility where you download a real "Example-2.pdf", and can't associate it to the original filename.
You can grab the number of like-named files either by reading _files.txt or counting the number of files in the directory.
Personally, I'd also suggest storing the files in a tiered bucketing system, so that you don't have too many files/directories in any one directory (hundreds of files makes it annoying as a user, thousands of files can affect OS performance ). A bucketing system might turn a filename into a hexdigest, then drop the file into `/%s/%s/%s" % ( hex[0:3], hex[3:6], filename ). The hexdigest is used to give you a more even distribution of characters.
import os
def uniquify(path, sep=''):
path = os.path.normpath(path)
num = 0
newpath = path
dirname, basename = os.path.split(path)
filename, ext = os.path.splitext(basename)
while os.path.exists(newpath):
newpath = os.path.join(dirname, '{f}{s}{n:d}{e}'
.format(f=filename, s=sep, n=num, e=ext))
num += 1
return newpath
filename = uniquify('foo.pdf', sep='_')
Possible problems with this include:
If you call to uniquify many many thousands of times with the same
path, each subsequent call may get a bit slower since the
while-loop starts checking from num=0 each time.
uniquify is vulnerable to race conditions whereby a file may not
exist at the time os.path.exists is called, but may exist at the
time you use the value returned by uniquify. Use
tempfile.NamedTemporaryFile to avoid this problem. You won't get
incremental numbering, but you will get files with unique names,
guaranteed not to already exist. You could use the prefix parameter to
specify the original name of the file. For example,
import tempfile
import os
def uniquify(path, sep='_', mode='w'):
path = os.path.normpath(path)
if os.path.exists(path):
dirname, basename = os.path.split(path)
filename, ext = os.path.splitext(basename)
return tempfile.NamedTemporaryFile(prefix=filename+sep, suffix=ext, delete=False,
dir=dirname, mode=mode)
else:
return open(path, mode)
Which could be used like this:
In [141]: f = uniquify('/tmp/foo.pdf')
In [142]: f.name
Out[142]: '/tmp/foo_34cvy1.pdf'
Note that to prevent a race-condition, the opened filehandle -- not merely the name of the file -- is returned.

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