How do I copy a file in Python?

Question

How do I copy a file in Python?

I couldn\'t find anything under os.

Answer 1

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)

Answer 2

┌──────────────────┬────────┬───────────┬───────┬────────────────┐
│     Function     │ Copies │   Copies  │Can use│   Destination  │
│                  │metadata│permissions│buffer │may be directory│
├──────────────────┼────────┼───────────┼───────┼────────────────┤
│shutil.copy       │   No   │    Yes    │   No  │      Yes       │
│shutil.copyfile   │   No   │     No    │   No  │       No       │
│shutil.copy2      │  Yes   │    Yes    │   No  │      Yes       │
│shutil.copyfileobj│   No   │     No    │  Yes  │       No       │
└──────────────────┴────────┴───────────┴───────┴────────────────┘

Answer 3

As of Python 3.5 you can do the following for small files (ie: text files, small jpegs):

from pathlib import Path

source = Path('../path/to/my/file.txt')
destination = Path('../path/where/i/want/to/store/it.txt')
destination.write_bytes(source.read_bytes())

write_bytes will overwrite whatever was at the destination's location

Answer 4

For large files, what I did was read the file line by line and read each line into an array. Then, once the array reached a certain size, append it to a new file.

for line in open("file.txt", "r"):
    list.append(line)
    if len(list) == 1000000: 
        output.writelines(list)
        del list[:]

Answer 5

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)

---

Answer 6

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.