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matplotlib

Image Size

  • Create a figure with the specified size: plt.figure(figsize=(w,h))

  • Default size: plt.figure(figsize=(6.4,4.8))

  • Adjust default plot size:

    import matplotlib
plt.rcParams['figure.figsize'] = [width, height]

tmux

  • tmux attach -t 0: Attach to session 0
  • Ctrl + b + Arrow Keys: Switch to the session in the specified direction
  • Ctrl + b + Number: Switch to the session with the specified number
  • Ctrl + b + d: Return to shell while keeping the session alive
  • Ctrl + c + Ctrl + c: Close emacs

Python

Execution Path os.getcwd()

  • main.__file__: Get the path including the filename and extension.
  • os.path.dirname(os.path.realpath(__file__)): Get the path of the folder containing the file. Use this to ensure functionality when executing Python files from the terminal.
  • os.getcwd(): Get the current working directory. Works as intended when executing *.py files from the explorer, but returns the terminal path when run from the terminal.
>>> import os
>>> import __main__ as main

>>> x = main.__file__
>>> print(x, "\n")
C:/Users/admin/Desktop/Python/test.py

>>> y = os.path.dirname(os.path.realpath(__file__))
>>> print(y, "\n")
C:/Users/admin/Desktop/Python

>>> z = os.getcwd()
>>> print(z)
C:/Users/admin/Desktop/Python

Check if Path Exists os.path.exists(directory)

  • os.path.exists(directory): Returns True or False based on whether the path exists.

Create Folder os.makedirs(directory)

  • os.makedirs(directory): Creates a folder if the entered path does not exist.
    def create_directory(directory):
    try:
        if not os.path.exists(directory):
            os.makedirs(directory)
    except OSError:
        print("Error: Failed to create the directory.")

Delete Folder

Code to delete empty folders while traversing subfolders.

import os

directory = os.path.dirname(os.path.realpath(__file__))

for (path, dir, files) in os.walk(directory):
    try:
        os.removedirs(str(path))
    except:
        print("디렉토리가 비어있지 않습니다.")

Find Specific Files in Subdirectories of the Running File

Code to find all Python files in the folder where the execution file is located, including its subdirectories. The folder containing the execution file is also included in the search range, so the execution file itself is included in the file_list.

directory = os.getcwd()
file_list = []

for (path, dir, files) in os.walk(directory):
    for filename in files:
        ext = os.path.splitext(filename)[-1]
        if ext == '.py':
            file_list.append("%s\\%s" % (path, filename))

Execution Variables sys.argv

Receiving the part after python using sys.argv = foo.split().

# 파일 실행
import os 

os.system("python " + "file_directory/foo.py " + argv1 + " " + argv2)

## foo.py 내부 코드
import sys

# sys.argv[0]는 "file_directory/foo.py "임
variable1 = sys.argv[1]
variable2 = sys.argv[2]

File Reading and Writing

Reading and writing should be done separately. Adding “t” indicates text mode, “b” indicates binary mode.

  • “rt” is read-text mode, read-only, throws an error if file does not exist
  • “w” is write mode, creates a new file regardless of whether it exists
  • “a” is append mode, creates a new file if it does not exist, otherwise appends to the end of the existing file
  • “x” is create mode, throws an error if the file already exists
# 텍스트 파일 열고 내용 가져오기, 그리고 닫기
foo_read = open(file_directory + "foo.txt", "rt", encoding="utf-8")
lines = foo_read.readlines()
foo_read.close()

readlines() reads each line of a txt file as an element (string) in a list. If there is a newline character, '\n' is also included at the end. The .strip() method can be used to remove the trailing '\n'.

foo_write = open(file_directory + "foo.txt", "wt", encoding="utf-8")

foo_write.write("bar\n") # 한 줄 쓰기

lines = ["bar1\n", "bar2\n", "bar3\n"]
foo_write.lines(lines) # 여러 줄 쓰기
foo_write.close()

Strings

  • strip(): Removes characters from both ends of a string. Without a variable, it removes whitespaces (including newlines). Useful for removing spaces at the start and end of a string.
  • sort(): Sorts strings in alphabetical order. For reverse order, use reverse=True.
  • replace(): Replaces a substring within a string.
  • translate(): Replaces characters within a string.

    Difference between replace and translate1

    replace(‘old_string’, ’new_string’) replaces the old substring with a new one within the string (the string itself is not changed, the result is returned). For example, replace ‘world’ with ‘Python’ in ‘Hello, world!’ and returns the result. while replace changes a substring, translate can be used to change individual characters. translate changes characters within a string. First, create a conversion table with str.maketrans(‘old_char’, ’new_char’), then use translate(table) to replace characters and return the result. For example, replace ‘a’ with 1, ’e’ with 2, ‘i’ with 3, ‘o’ with 4, and ‘u’ with 5 in the string ‘apple’.

    >>> table = str.maketrans('aeiou', '12345')
>>> 'apple'.translate(table)
'1ppl2'
  • split(): Splits a string into a list based on the input variable.
    >>> x.split(',')
['1', '3', '4']

Well-organized site

Lists

  • .sorted(): Sorts strings in alphabetical order. For reverse order, use reverse=True.

  • Save and load lists

import pickle

list = [1, 2, 3, 4]

# 리스트 저장
with open("list.pkl", "wb") as f:
    pickle.dump(list, f)

# 리스트 불러오기
with open("list.pkl", "rb") as f:
    list = pickle.load(f)

Julia

$\LaTeX$

Font Size

$\Huge AB$ \Huge AB

$\huge AB$ \huge AB

$\LARGE AB$ \LARGE AB

$\Large AB$ \Large AB

$\large AB$ \large AB

$\normalsize AB$ \normalsize AB

$\small AB$ \small AB

$\footnotesize AB$ \footnotesize AB

$\scriptsize AB$ \scriptsize AB

$\tiny AB$ \tiny AB

PyTorch and TensorFlow

GPU

Check GPU

  • P: torch.cuda.is_available()

Arrays

Constants

  • P: torch.tensor([1,2,3])
  • TF: tf.constant([1,2,3])

Parameters

  • P: torch.tensor([1,2,3], requires_grad=True)
  • TF: tf.variable([1,2,3])

Models

Class

  • P: class model(nn.Module)
  • TF: class model(tf.keras.Model)

TF: model.complie()

TF: model.fit(data, label, epochs, batch_size, verbose)

  • verbose: Integer. 0, 1, or 2. (Training output mode)
    • 0 = silent,
    • 1 = progress bar,
    • 2 = one line per epoch.

TF: model.complie()

VS Code

MarkdownAllinOne

Function for automatic Markdown table formatting: Shift + Alt + F

  • Prevent expanding folders when opening files: Explorer: Auto Reveal

Enable Auto Word Wrap

Automatic code word wrap: Editor: Word Wrap

  • Ctrl + Shift + P $\to$ Enable word wrap by searching word wrap
  • Toggle key: Alt + z

Automatically wrap tab strip: Editor: Wrap Tabs

Set Keyboard Shortcuts: keybindings.json

  • Path: C:/Users/user/AppData/Roaming/Code/User/keybindings.json

  • Automatically add parentheses in superscript within Markdown:

    {
  "key": "shift+6",
  "command": "editor.action.insertSnippet",
  "when": "editorTextFocus && editorLangId == 'markdown'",
  "args": {
    "snippet": "^{$0\\}"
  }
}
    • To apply it to .tex files, use editorLangId == 'latex'

  1. https://dojang.io/mod/page/view.php?id=2299 ↩︎