cape.fileutils: Pure-Python file information utilities

This module provides several file utilities that mimic common BASH commands or programs, but written in pure Python to remove operating system dependencies.

cape.fileutils.count_lines(fname: str) → int

Count lines in a file

Meant to mimic results of

$ wc -l $FNAME

but written in pure Python.

Call:
>>> n = count_lines(fname)
Inputs:
fname: str

Name of file to read

Outputs:
n: int

Number of lines in file

Versions:

  • 2024-07-15 @ddalle: v1.0

cape.fileutils.get_latest_file(filelist: list) → str

Get the latest modified file from a list of files

Call:
>>> fname = get_latest_file(filelist)
Inputs:
filelist: list[str]

List of file names

Outputs:
fname: str

Name of latest modified file in list

Version:

  • 2024-01-21 @ddalle: v1.0

cape.fileutils.get_latest_regex(pat: str, baseglob=None)

Get the latest modified file matching a regular expression

Call:
>>> fname, regmatch = get_latest_regex(pat, baseglob=None)
Inputs:
pat: str

Regular expression string

baseglob: {None} | str

Optional glob pattern to narrow candidates in current dir

Outputs:
fname: str

Name of latest modified file in list

regmatch: re.Match

Regular expression groups, etc. for fname

Version:

  • 2024-03-24 @ddalle: v1.0

cape.fileutils.grep(pat: str, fname: str, nmax: int | None = None, encoding: str = 'utf-8') → list

Find lines of a file containing a regular expressoin

Call:
>>> lines = grep(pat, fname, nmax=None, encoding="utf-8")
Inputs:
pat: str

String of regular expression pattern

fname: str

Name of file to search

nmax: {None} | int

Optional maximum number of matches to find

encoding: {"utf-8"} | str

Encoding for file

Outputs:
lines: list[str]

List of lines containing a match of pat

Versions:

  • 2023-06-16 @ddalle: v1.0

  • 2024-07-30 @ddalle: v1.1; add nmax

cape.fileutils.head(fname: str, n=1, encoding='utf-8') → str

Get first n lines of a file

Call:
>>> txt = head(fname, n=1)
Inputs:
fname: str

Name of file to read

n: {1} | int

Number of lines to read from beginning of file

encoding: {"utf-8"} | str

Encoding for text file

Versions:

  • 2023-06-16 @ddalle: v1.0

cape.fileutils.readline_reverse(fb: IOBase) → bytes

Read line ending at current position

Call:
>>> txt = readline_reverse(fb)
Inputs:
fb: IOBase

File handle open for reading in binary mode

Outputs:
txt: bytes

Encoded text of last line

Versions:

  • 2024-07-26 @ddalle: v1.0

cape.fileutils.sort_by_mtime(filelist: list) → list

Sort list of files by modification time (ascending)

Call:
>>> tfiles = sort_by_mtime(filelist)
Inputs:
filelist: list[str]

List of file names

Outputs:
tfiles: list[str]

Files of filelist in order of ascending modification time

Version:

  • 2024-01-21 @ddalle: v1.0

cape.fileutils.tail(fname: str, n=1, encoding='utf-8')

Get last n lines of a file

Call:
>>> txt = tail(fname, n=1)
Inputs:
fname: str

Name of file to read

n: {1} | int

Number of lines to read from end of file

encoding: {"utf-8"} | str

Encoding for text file

Outputs:
txt: str

Text of last n lines of fname

Versions:

  • 2023-06-16 @ddalle: v1.0

cape.fileutils.touch(fname: str)

Replicate touch; creating new file or updating mod time

Call:
>>> touch(fname)
Inputs:
fname: str

Name of file to create/modify

Versions:

  • 2023-06-16 @ddalle: v1.0