Five .ipynb Language Tutorial

Thanks for contribution 🤗:

https://github.com/ShixiangWang/iLearning/blob/master/study/Python/learnPython/搞定Python基本操作.ipynb https://github.com/rajathkmp/Python-Lectures/blob/master/03.ipynb https://jupyter.org/try-jupyter/lab/index.html?fromURL=https://gist.githubusercontent.com/kenjyco/69eeb503125035f21a9d/raw/learning-python3.ipynb https://github.com/jamwine/Python-Beginners-Guide/blob/master/Learn%20Python%20in%20Jupyter%20Notebook.ipynb https://github.com/cs231n/cs231n.github.io/blob/master/python-colab.ipynb

for i in {2..6}; do printf " [🦄](https://jupyter.org/try-jupyter/lab/index.html?fromURL=https://gist.githubusercontent.com/duangsuse/519411ab618ee57350ee2df93d33f58e/raw/$i.ipynb)"; done

🦄 🦄 🦄 🦄 🦄

open a link above, CtrlV, ShiftEnter to run code below.

# <3 Python is REALLY simple, differ from MOST popular languages eg. Java C PHP Ruby 
# 💯 CtrlL https://hellogithub.com/en/report/tiobe 

# No "$" or "-" for var_x/defX/ClassX Names, no ^[0-9] at start.
# indentation & case sensitive, use Tab / Shift+Tab / ?var for docs

["It's not from TOML.io !"]
name = "Alice"      # String
age = 30            # Integer, 10//3 is 3
usdt = 19.99        # Float (USE 1999 FOR BALANCE)
is_active = True    # use with if bool(x):
hex2 = 0xdeadbeef   # int, 0xHex format

prices = {"Apple": 1.99, "Banana": 0.99}
fruits = ["Apple", "Banana", "Cherry"]
top1_fruit = fruits[i:=0]  # try i in range(0, < 3), or row[0:3] slice (supports -1=len()-1)

Composing flow

Compose statement literal containing API callgraph(': block' s) & vartree(GC values), reuse app functions with def(vars):

subprocess.getoutput

n=3 3 3
Hello 5
typed 5
world 5
[('Hello', 5), ('typed', 5), ('world', 5)] [('Hello', 5), ('typed', 5), ('world', 5)]

list(kv)=['Hello', 'typed', 'world']
kv={}
kv['Hello'] = 5
kv['typed'] = 5
kv['world'] = 5
two十(3)=5 666
two十(3)=5 669
More

# for(n=0, i=0;i<3;i+=1) n+=i
n = 0
for i in (rn := range(0, 3)):
  n += i

print(f"{n=}", sum(i + 0 for i in range(0, 3)), sum(rn))

words = "Hello typed  world  ".split(" ")
stdo = []
for w in words:
  if w != "":
    print(w, len(w))
for w in words:
  stdo.append((w, len(w))) if w != "" else None

print(stdo, kv := [(u, len(u)) for u in words], end="\n" * 2)

"deleteMe" or kv.pop(-1)  # , retWhenNone
kv = dict(kv)  # vartype shadowing
print(f"{list(kv)=}")  # = [*kv]
"duck🦆" or kv.pop("typed")

print("kv={}")  # 👎 C-style boilerplates
for col in kv.items():
  k, v = map(repr, col)  # json-compat literal_eval?
  if "explicit":
    k, v = (repr(u) for u in col)
  print(f"kv[{k}] = {v}")


def make_十(n):
  return lambda x: x + n


two十 = make_十(2)
print(f"{two十(3)=}", two十(664))

from argparse import Namespace


def cell_十(n=0):  # constructor(var n)
  def javaSAM(step):
    nonlocal n  # 👍 Py: no let-var style declarations, no (this.n)
    n += step
    return n

  return Namespace(inc=javaSAM)


two十 = cell_十(2).inc
print(f"{two十(3)=}", two十(664))

x = int(input("Please enter an integer: "))
if x < 0:
  x = 0
  print("Negative changed to zero")
elif x == 0:
  print("Zero")
elif x == 1:
  print("Single")
else:
  print("More")

# Let's extract the input(stdin.line),
# and make print a 'callback' by return(str) to sys callstack


def numKind(num):
  match num:
    case 0: it = "Zero"
    case 1: it = "Single"
    case x if x < 0:
      it = f"Negative ({x})"
    case _: it = "Normal"
  return it
  # it = match num: or "match num as it" are unsupported.


def tryInt(s: "123"):
  try:
    return int(s)
  except:
    return None


while "REPL":
  n = tryInt(input("integer: ").strip())
  if not n and n != 0:
    break
  # ^ Oops, NaN means 'invalid input', (0) ALSO DOES? so could nan be Falsey? .: bool(math.nan)
  print(numKind(n))

For spreadsheet guys

import io, pandas as pd
import matplotlib.pyplot as plt

STORE = """csv
Apple,Banana,Cherry
1,2,3
1.99,0.99,2
"""

# module_KV, class, def/arg:Type, (lambda nonlocalVars, codetree..) are ALL DICT AND 'k=v's in Python3.
for k in globals():
  if not all(c.isupper() for c in k):
    continue  # if /^[A-Z]+$/: replaceIt()  # tool regex101.com
  ext, mem = eval(f"{k}").split("\n", 1)  # v with(globalThis) of module.py
  exec(f"{k} = pd.read_{ext}(io.StringIO(mem))")


def main():
  df = STORE
  aapl_sales = df[df["Apple"] > 1]
  all = df.sum()
  # df.to_excel("out_store.xlsx", index=False)
  display(*vars().keys())
  display(*vars().values())

  df["Sale"] = df["Apple"] + df["Banana"]
  df["Sale"].plot(kind="line")
  plt.title("Units Sold Over Time")
  plt.show()


main()

For API designer, metaprogramming

#def With(u, f):  call eg.  With(Box(1), lambda x: x.As(x.v+1)), too long
def With(u):
  def PipeBy(f): f(u); return u
  return PipeBy

@With({})
def js(u):
  u['A'] = 1

print(js) # Yeah, @decorator are just fncall.  cout<< are operator<<(call), printf() are syscall(write,fd=0)
# They're FAKE SYNTAX, but idioms are not constant.

from dataclasses import dataclass, field
def data(T):
  'Trick: create vartree containers w/o def __init__ or call([],{})'
  {setattr(T, k, field(default_factory=v if isFn else v.copy)) for k,v in T.__annotations__.items() if (isFn:=callable(v))or hasattr(v,'copy')}
  return dataclass(T)

@data
class UserQueue:
  id: list
  usd: dict
  def onBuy(u, id):
    u.id.append(id)
    u.usd[id]=100
  def _repr_markdown_(u):
    get_ipython().__class__.__name__
    #^ https://ipython.readthedocs.io/en/stable/config/integrating.html
    return "".join(f"- [{me}]() **\\${u.usd[me]/100}**\n" for me in u.id)



@With(UserQueue())
def uq(u):
  [u.onBuy(id) for id in "Amy Jack Rose".split()]
  u.usd['Jack']=10_000
display(uq)

# got tired of `def try$Int` templates?
# cool @decorator to convert raise ValueError() to None
def tryFill(op, v0=None):
  def safe(*a, **kw):
    try: return op(*a, **kw)
    except: return (v0(a[0]) if callable(v0) else v0)
  return safe


@tryFill
def faulty(x):
  if x: raise x
  return x

if "": # edit, re-run!
    @tryFill
    def faulty(a):
      try:
        for x in a: raise x
      except TypeError: pass

tryFill(int)('abc'), tryFill(int, len)('abc')

HTTPd echo

4 major IO demo: EchoArgs, Counter, Checklist_DDL, SplitJoinWalk

first one (async Flask + cookie):

#sudo setcap 'cap_net_bind_service=+pie' /usr/bin/python3.*

from fastapi import FastAPI, Request
from fastapi.responses import Response
from uvicorn import run as bun
from pydantic import BaseModel, Field

I = FastAPI()

if "real world":

  @I.get("/login")
  async def setJsGlobal():
    # Create response with login message
    rpc = Response("Login successful. Session address set.")

    # Set session cookie with 1-day expiration
    rpc.set_cookie(
      key="USER",
      value="objectID",  # In production, use a hash(random+salt) token
      max_age=dur,
      expires=dur,
      path="/",  # Cookie available for HOST/*
      secure=False,  # Set to True in production with HTTPS
      httponly=True,  # Prevent XSS attacks
      samesite="lax",  # Prevent CSRF with modern browsers
    )
    return rpc

  class Blog(BaseModel):
    "try connect DB"

    id: int = Field(None, description="TBD, eg. UUID, auto-increment")
    slug: str = Field(min_length=4, max_length=15)
    html: str = Field(min_length=1, max_length=3000)  # no optional, age range


# @I.get("/{path:path}")
async def echo(path: str, u: Request):
  output = [
    f"curl $I/{path}",
    f"location.search: {u.query_params}",
    "Body: None (call PUT for write)\n\n",
    f"Client IP: {u.client.host}",
  ]
  auth(output, u)
  output.append("kwargs = {")
  for key, value in u.headers.items():  # try shorten!
    output.append(f"  {key} = {value}, ")
  output.append("}\n")

  return Response(content="\n".join(output), media_type="text/plain")


superFn = echo
@I.get("/{path}") # dont GET /
async def echo(
  path: str,
  q: str = "",
  p: int = 1,
  sort: str = "-1create_at",
  per_page: int = 100,
  u: Request = None,
):
  curs = (p - 1) * per_page
  res = await superFn(path, u)  # middleware are just "override fun" or pipes
  return Response(
    f"db.filter({q})[{curs}:{curs + per_page}].sort_({sort})\n".encode() + res.body
  )


@I.post("/{path}")
async def echo(path: str, u: Request):  # orderBy created, [0 1 2..]
  output = [
    "",
    f"location.search: {u.query_params}",
    f"Client IP: {u.client.host}",
  ]
  auth(output, u)  # try sort output!
  (output.append)("kwargs:")
  for key, value in u.headers.items():  # try shorten!
    output.append(f"  {key}: {value}")

  body = await u.body()
  output.append(f"\nBody ({len(body)} bytes/octects):")
  output.append(crud := body.decode("utf-8", errors="ignore"))
  output[0] = f"curl $I/{path} -d@'-' <<<{repr(crud)}"
  return Response(content="\n".join(output), media_type="text/plain")


if __name__ == "__main__":
  dur = 10 or 86400  # 24 hours in seconds
  foreign = {
    "objectID": f"Proxy.revocable(SQL_pointer,{dur}s)",
    None: "readonly, no-REST",
  }
  auth = lambda ln, u: ln.append(
    f"SK_ *(&api): {foreign.get(u.cookies.get('USER', None), 'expired')}"
  )
  bun(I, host="0.0.0.0", port=8080)
  if "fetch() fail":
    see = "https://fastapi.tiangolo.com/tutorial/cors/#use-corsmiddleware"
    see = "https://jsonplaceholder.typicode.com/"

if "f-string and let-match were not born" or "ES6 = uglify JS":
  from bottle import route, run, template

  @route('/hello/<name>')
  def index(name):
      return template('<b>Hello {{name}}</b>!', name=name)

  run(host='localhost', port=8080)

• In memory of my Ruby tutorial @2018, Channel [email protected]