How do I copy a file in Python?

copy2(src,dst) is often more useful than copyfile(src,dst) because:

• it allows dst to be a directory (instead of the complete target filename), in which case the basename of src is used for creating the new file;
• it preserves the original modification and access info (mtime and atime) in the file metadata (however, this comes with a slight overhead).

Here is a short example:

import shutil
shutil.copy2('/src/dir/file.ext', '/dst/dir/newname.ext') # complete target filename given
shutil.copy2('/src/file.ext', '/dst/dir') # target filename is /dst/dir/file.ext

You can use one of the copy functions from the shutil package:

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Function              preserves     supports          accepts     copies other
                      permissions   directory dest.   file obj    metadata  
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shutil.copy              ✔             ✔                 ☐           ☐
shutil.copy2             ✔             ✔                 ☐           ✔
shutil.copyfile          ☐             ☐                 ☐           ☐
shutil.copyfileobj       ☐             ☐                 ✔           ☐
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

Example:

import shutil
shutil.copy('/etc/hostname', '/var/tmp/testhostname')

In Python, you can copy the files using

• shutil module
• os module
• subprocess module

import os
import shutil
import subprocess

1) Copying files using shutil module

shutil.copyfile signature

shutil.copyfile(src_file, dest_file, *, follow_symlinks=True)

# example    
shutil.copyfile('source.txt', 'destination.txt')

shutil.copy signature

shutil.copy(src_file, dest_file, *, follow_symlinks=True)

# example
shutil.copy('source.txt', 'destination.txt')

shutil.copy2 signature

shutil.copy2(src_file, dest_file, *, follow_symlinks=True)

# example
shutil.copy2('source.txt', 'destination.txt')  

shutil.copyfileobj signature

shutil.copyfileobj(src_file_object, dest_file_object[, length])

# example
file_src = 'source.txt'  
f_src = open(file_src, 'rb')

file_dest = 'destination.txt'  
f_dest = open(file_dest, 'wb')

shutil.copyfileobj(f_src, f_dest)  

2) Copying files using os module

os.popen signature

os.popen(cmd[, mode[, bufsize]])

# example
# In Unix/Linux
os.popen('cp source.txt destination.txt') 

# In Windows
os.popen('copy source.txt destination.txt')

os.system signature

os.system(command)


# In Linux/Unix
os.system('cp source.txt destination.txt')  

# In Windows
os.system('copy source.txt destination.txt')

3) Copying files using subprocess module

subprocess.call signature

subprocess.call(args, *, stdin=None, stdout=None, stderr=None, shell=False)

# example (WARNING: setting `shell=True` might be a security-risk)
# In Linux/Unix
status = subprocess.call('cp source.txt destination.txt', shell=True) 

# In Windows
status = subprocess.call('copy source.txt destination.txt', shell=True)

subprocess.check_output signature

subprocess.check_output(args, *, stdin=None, stderr=None, shell=False, universal_newlines=False)

# example (WARNING: setting `shell=True` might be a security-risk)
# In Linux/Unix
status = subprocess.check_output('cp source.txt destination.txt', shell=True)

# In Windows
status = subprocess.check_output('copy source.txt destination.txt', shell=True)

Copying a file is a relatively straightforward operation as shown by the examples below, but you should instead use the shutil stdlib module for that.

def copyfileobj_example(source, dest, buffer_size=1024*1024):
    """      
    Copy a file from source to dest. source and dest
    must be file-like objects, i.e. any object with a read or
    write method, like for example StringIO.
    """
    while True:
        copy_buffer = source.read(buffer_size)
        if not copy_buffer:
            break
        dest.write(copy_buffer)

If you want to copy by filename you could do something like this:

def copyfile_example(source, dest):
    # Beware, this example does not handle any edge cases!
    with open(source, 'rb') as src, open(dest, 'wb') as dst:
        copyfileobj_example(src, dst)

Use the shutil module.

copyfile(src, dst)

Copy the contents of the file named src to a file named dst. The destination location must be writable; otherwise, an IOError exception will be raised. If dst already exists, it will be replaced. Special files such as character or block devices and pipes cannot be copied with this function. src and dst are path names given as strings.

Take a look at filesys for all the file and directory handling functions available in standard Python modules.