7.1. File Path¶

7.1.1. Rationale¶

Never hardcode paths (put path directly to open function)

Use constant as a file name or file path

Convention FILE, FILENAME, FILEPATH, PATH

Or their respective plural forms for multiple files

Note, that PATH is usually used for other purposes (sys.path or os.getenv('PATH'))

Always use raw-strings r"..."

Paths on Windows uses \

Paths on *nix uses /

*nix operating systems: Linux, macOS, BSD and other POSIX compliant OSes (excluding Windows)

In newer Windows versions both \ and / works

7.1.2. Absolute Path¶

Absolute path on Windows starts with drive letter

Absolute path on *nix starts with root / dir

Absolute path include all entries in the directories hierarchy

FILE = r'C:\Users\Watney\myfile.txt'

FILE = r'/tmp/myfile.txt'

7.1.3. Relative Path¶

Path is relative to currently running script

. - Current directory

.. - Parent directory

FILE = r'myfile.txt'
FILE = r'./myfile.txt'

FILE = r'tmp/myfile.txt'
FILE = r'./tmp/myfile.txt'

FILE = r'../myfile.txt'
FILE = r'../tmp/myfile.txt'

FILE = r'../../myfile.txt'
FILE = r'../../tmp/myfile.txt'

7.1.4. Escaping Characters in Path¶

"\ " (slash space) - escapes space

Note escapes are not needed

FILE = '/tmp/my file.txt'

with open(FILE) as file:
    print(file.read())

# Success!

FILE = r'/tmp/my file.txt'

with open(FILE) as file:
    print(file.read())

# Success!

FILE = r'C:\Users\Admin\myfile.txt'

repr(FILE)
# "'C:\\\\Users\\\\Admin\\\\myfile.txt'"

str(FILE)
# 'C:\\Users\\Admin\\myfile.txt'

print(repr(FILE))
# 'C:\\Users\\Admin\\myfile.txt'

print(FILE)
# C:\Users\Admin\myfile.txt

7.1.5. Create Directories¶

from os import mkdir


mkdir('/tmp/a')
# directory /tmp/a created

mkdir('/tmp/a/b/c')
# FileNotFoundError: [Errno 2] No such file or directory: '/tmp/a/b/c'

from os import makedirs


makedirs('/tmp/a')
# directory /tmp/a created

makedirs('/tmp/a')
# FileExistsError: [Errno 17] File exists: '/tmp/a'

makedirs('/tmp/a', exist_ok=True)
# No error

makedirs('/tmp/a/b/c')
# directory /tmp/a/b/c created

7.1.6. Exists and is Directory or File¶

from pathlib import Path


path = Path(r'/tmp/myfile.txt')

path.exists()
# True

path.is_dir()
# False

path.is_file()
# True

7.1.7. Current Working Directory¶

Returns an absolute path to current working directory

from pathlib import Path

Path.cwd()
# PosixPath('/home/python/')

7.1.8. Convert Relative Path to Absolute¶

from pathlib import Path


Path(Path.cwd(), 'myfile.txt')
# PosixPath('/home/python/myfile.txt')

7.1.9. Script Path¶

Returns an absolute path to currently running script

print(__file__)
# /home/python/myscript.py

7.1.10. Assignments¶

7.1.10.1. File Path Abspath¶

Complexity level: easy
Lines of code to write: 5 lines
Estimated time of completion: 5 min
Solution: solution/file_path_abspath.py

English

Using input() ask user for a file path
Convert path to absolute
Print if path exists and leads to file or directory

Polish

Używając input() zapytaj użytkownika o ścieżkę do pliku
Przekonwertuj ścieżkę do bezwzględnej
Wypisz czy ścieżka istnieje i czy prowadzi do pliku czy katalogu