如何合并目录中除指定文件之外的所有文件？

Question

I want to merge all files with the extension .asc in my current working directory to be merged into a file called outfile.asc .

My problem is, I don't know how to exclude a specific file ( "BigTree.asc" ) and how to overwrite an existing "outfile.asc" if there is one in the directory.

if len(sys.argv) < 2:
    print("Please supply the directory of the ascii files and an output-file as argument:")
    print("python merge_file.py directory outfile")
    exit()
directory = sys.argv[1]

os.chdir(directory)
currwd = os.getcwd()

filename = sys.argv[2]
fileobj_out = open(filename, "w") 

starttime = time.time()

read_files = glob.glob(currwd+"\*.asc")

with open("output.asc", "wb") as outfile:
    for f in read_files:
        with open(f, "rb") as infile:
            if f == "BigTree.asc":
                continue
            else:
                outfile.write(infile.read())

endtime = time.time()
runtime = int(endtime-starttime)
sys.stdout.write("The script took %i sec." %runtime)

Answer 1

The problem is that glob takes the filenames with fullpath. I did some minor changes that should work on your code now. For instance, instead of using == use in .

if len(sys.argv) < 2:
    print("Please supply the directory of the ascii files and an output-file as argument:")
    print("python merge_file.py directory outfile")
    exit()
directory = sys.argv[1]

os.chdir(directory)

filename = sys.argv[2]
fileobj_out = open(filename, "w") 

starttime = time.time()

read_files = glob.glob(currwd+"\*.asc")

# Change [1]
with open("output.asc", "ab") as outfile:
    for f in read_files:
        with open(f, "rb") as infile:
            # Change [2] '==' for 'in'
            if "BigTree.asc" in f:
                continue
            else:
                outfile.write(infile.read())

endtime = time.time()
runtime = int(endtime-starttime)
sys.stdout.write("The script took %i sec." %runtime)

Explanation

[1] Changed the file mode from 'wb' (write byte mode) to 'ab' (append byte mode), in this way if the file exists, it will append the information to it.

[2] Changed "==" for "in" in this way, if the file name f contains the string BigTree.asc it will skip this file and continue.

Please let me know if this helps!

Thanks:D

Answer 2

Giving the following section of your code

with open("output.asc", "wb") as outfile:
    for f in read_files:
        with open(f, "rb") as infile:
            if f == "BigTree.asc":
                continue
            else:
                outfile.write(infile.read())

Updated section

1. Change open("output.asc", "wb") to use filename from filename = sys.argv[2]
   • If output.asc is the second argument, it will be overwritten ( wb ) or appended to ( ab ) depending on the specified mode.
2. Opening the unused file is inefficient
   • Check for BigTree.asc before opening the file, with not in
   • Use negative conditionals as guard clauses to flatten your code.

with open(filename, "wb") as outfile:
    for f in read_files:
        if "BigTree.asc" not in f:
            with open(f, "rb") as infile:
                outfile.write(infile.read())

Reading and writing modes

| Access Modes | Description                                                   |
|--------------|---------------------------------------------------------------|
| r            | Opens a file for reading only.                                |
| rb           | Opens a file for reading only in binary format.               |
| r+           | Opens a file for both reading and writing.                    |
| rb+          | Opens a file for both reading and writing in binary format.   |
| w            | Opens a file for writing only.                                |
| wb           | Opens a file for writing only in binary format.               |
| w+           | Opens a file for both writing and reading.                    |
| wb+          | Opens a file for both writing and reading in binary format.   |
| a            | Opens a file for appending.                                   |
| ab           | Opens a file for appending in binary format.                  |
| a+           | Opens a file for both appending and reading.                  |
| ab+          | Opens a file for both appending and reading in binary format. |

Full Program

• This line fileobj_out = open(filename, "w") should be removed

import glob
import sys
import os
import time


if len(sys.argv) < 2:
    print("Please supply the directory of the ascii files and an output-file as argument:")
    print("python merge_file.py directory outfile")
    exit()
directory = sys.argv[1]

os.chdir(directory)

currwd = os.getcwd()

filename = sys.argv[2]

starttime = time.time()

read_files = glob.glob(currwd+"\*.asc")

with open(filename, "wb") as outfile:  # "wb" or "ab", if you want to append or not
    for f in read_files:
        if "BigTree.asc" not in f:
            with open(f, "rb") as infile:
                outfile.write(infile.read())

endtime = time.time()
runtime = int(endtime-starttime)
sys.stdout.write("The script took %i sec." %runtime)