Graduationwoot

Dragon Notes

i

\( \newcommand{bvec}[1]{\overrightarrow{\boldsymbol{#1}}} \newcommand{bnvec}[1]{\overrightarrow{\boldsymbol{\mathrm{#1}}}} \newcommand{uvec}[1]{\widehat{\boldsymbol{#1}}} \newcommand{vec}[1]{\overrightarrow{#1}} \newcommand{\parallelsum}{\mathbin{\|}} \) \( \newcommand{s}[1]{\small{#1}} \newcommand{t}[1]{\text{#1}} \newcommand{tb}[1]{\textbf{#1}} \newcommand{ns}[1]{\normalsize{#1}} \newcommand{ss}[1]{\scriptsize{#1}} \newcommand{vpl}[]{\vphantom{\large{\int^{\int}}}} \newcommand{vplup}[]{\vphantom{A^{A^{A^A}}}} \newcommand{vplLup}[]{\vphantom{A^{A^{A^{A{^A{^A}}}}}}} \newcommand{vpLup}[]{\vphantom{A^{A^{A^{A^{A^{A^{A^A}}}}}}}} \newcommand{up}[]{\vplup} \newcommand{Up}[]{\vplLup} \newcommand{Uup}[]{\vpLup} \newcommand{vpL}[]{\vphantom{\Large{\int^{\int}}}} \newcommand{lrg}[1]{\class{lrg}{#1}} \newcommand{sml}[1]{\class{sml}{#1}} \newcommand{qq}[2]{{#1}_{\t{#2}}} \newcommand{ts}[2]{\t{#1}_{\t{#2}}} \) \( \newcommand{ds}[]{\displaystyle} \newcommand{dsup}[]{\displaystyle\vplup} \newcommand{u}[1]{\underline{#1}} \newcommand{tu}[1]{\underline{\text{#1}}} \newcommand{tbu}[1]{\underline{\bf{\text{#1}}}} \newcommand{bxred}[1]{\class{bxred}{#1}} \newcommand{Bxred}[1]{\class{bxred2}{#1}} \newcommand{lrpar}[1]{\left({#1}\right)} \newcommand{lrbra}[1]{\left[{#1}\right]} \newcommand{lrabs}[1]{\left|{#1}\right|} \newcommand{bnlr}[2]{\bn{#1}\left(\bn{#2}\right)} \newcommand{nblr}[2]{\bn{#1}(\bn{#2})} \newcommand{real}[1]{\Ree\{{#1}\}} \newcommand{Real}[1]{\Ree\left\{{#1}\right\}} \newcommand{abss}[1]{\|{#1}\|} \newcommand{umin}[1]{\underset{{#1}}{\t{min}}} \newcommand{umax}[1]{\underset{{#1}}{\t{max}}} \newcommand{und}[2]{\underset{{#1}}{{#2}}} \) \( \newcommand{bn}[1]{\boldsymbol{\mathrm{#1}}} \newcommand{bns}[2]{\bn{#1}_{\t{#2}}} \newcommand{b}[1]{\boldsymbol{#1}} \newcommand{bb}[1]{[\bn{#1}]} \) \( \newcommand{abs}[1]{\left|{#1}\right|} \newcommand{ra}[]{\rightarrow} \newcommand{Ra}[]{\Rightarrow} \newcommand{Lra}[]{\Leftrightarrow} \newcommand{rai}[]{\rightarrow\infty} \newcommand{ub}[2]{\underbrace{{#1}}_{#2}} \newcommand{ob}[2]{\overbrace{{#1}}^{#2}} \newcommand{lfrac}[2]{\large{\frac{#1}{#2}}\normalsize{}} \newcommand{sfrac}[2]{\small{\frac{#1}{#2}}\normalsize{}} \newcommand{Cos}[1]{\cos{\left({#1}\right)}} \newcommand{Sin}[1]{\sin{\left({#1}\right)}} \newcommand{Frac}[2]{\left({\frac{#1}{#2}}\right)} \newcommand{LFrac}[2]{\large{{\left({\frac{#1}{#2}}\right)}}\normalsize{}} \newcommand{Sinf}[2]{\sin{\left(\frac{#1}{#2}\right)}} \newcommand{Cosf}[2]{\cos{\left(\frac{#1}{#2}\right)}} \newcommand{atan}[1]{\tan^{-1}({#1})} \newcommand{Atan}[1]{\tan^{-1}\left({#1}\right)} \newcommand{intlim}[2]{\int\limits_{#1}^{#2}} \newcommand{lmt}[2]{\lim_{{#1}\rightarrow{#2}}} \newcommand{ilim}[1]{\lim_{{#1}\rightarrow\infty}} \newcommand{zlim}[1]{\lim_{{#1}\rightarrow 0}} \newcommand{Pr}[]{\t{Pr}} \newcommand{prop}[]{\propto} \newcommand{ln}[1]{\t{ln}({#1})} \newcommand{Ln}[1]{\t{ln}\left({#1}\right)} \newcommand{min}[2]{\t{min}({#1},{#2})} \newcommand{Min}[2]{\t{min}\left({#1},{#2}\right)} \newcommand{max}[2]{\t{max}({#1},{#2})} \newcommand{Max}[2]{\t{max}\left({#1},{#2}\right)} \newcommand{pfrac}[2]{\frac{\partial{#1}}{\partial{#2}}} \newcommand{pd}[]{\partial} \newcommand{zisum}[1]{\sum_{{#1}=0}^{\infty}} \newcommand{iisum}[1]{\sum_{{#1}=-\infty}^{\infty}} \newcommand{var}[1]{\t{var}({#1})} \newcommand{exp}[1]{\t{exp}\left({#1}\right)} \newcommand{mtx}[2]{\left[\begin{matrix}{#1}\\{#2}\end{matrix}\right]} \newcommand{nmtx}[2]{\begin{matrix}{#1}\\{#2}\end{matrix}} \newcommand{nmttx}[3]{\begin{matrix}\begin{align} {#1}& \\ {#2}& \\ {#3}& \\ \end{align}\end{matrix}} \newcommand{amttx}[3]{\begin{matrix} {#1} \\ {#2} \\ {#3} \\ \end{matrix}} \newcommand{nmtttx}[4]{\begin{matrix}{#1}\\{#2}\\{#3}\\{#4}\end{matrix}} \newcommand{mtxx}[4]{\left[\begin{matrix}\begin{align}&{#1}&\hspace{-20px}{#2}\\&{#3}&\hspace{-20px}{#4}\end{align}\end{matrix}\right]} \newcommand{mtxxx}[9]{\begin{matrix}\begin{align} &{#1}&\hspace{-20px}{#2}&&\hspace{-20px}{#3}\\ &{#4}&\hspace{-20px}{#5}&&\hspace{-20px}{#6}\\ &{#7}&\hspace{-20px}{#8}&&\hspace{-20px}{#9} \end{align}\end{matrix}} \newcommand{amtxxx}[9]{ \amttx{#1}{#4}{#7}\hspace{10px} \amttx{#2}{#5}{#8}\hspace{10px} \amttx{#3}{#6}{#9}} \) \( \newcommand{ph}[1]{\phantom{#1}} \newcommand{vph}[1]{\vphantom{#1}} \newcommand{mtxxxx}[8]{\begin{matrix}\begin{align} & {#1}&\hspace{-17px}{#2} &&\hspace{-20px}{#3} &&\hspace{-20px}{#4} \\ & {#5}&\hspace{-17px}{#6} &&\hspace{-20px}{#7} &&\hspace{-20px}{#8} \\ \mtxxxxCont} \newcommand{\mtxxxxCont}[8]{ & {#1}&\hspace{-17px}{#2} &&\hspace{-20px}{#3} &&\hspace{-20px}{#4}\\ & {#5}&\hspace{-17px}{#6} &&\hspace{-20px}{#7} &&\hspace{-20px}{#8} \end{align}\end{matrix}} \newcommand{mtXxxx}[4]{\begin{matrix}{#1}\\{#2}\\{#3}\\{#4}\end{matrix}} \newcommand{cov}[1]{\t{cov}({#1})} \newcommand{Cov}[1]{\t{cov}\left({#1}\right)} \newcommand{var}[1]{\t{var}({#1})} \newcommand{Var}[1]{\t{var}\left({#1}\right)} \newcommand{pnint}[]{\int_{-\infty}^{\infty}} \newcommand{floor}[1]{\left\lfloor {#1} \right\rfloor} \) \( \newcommand{adeg}[1]{\angle{({#1}^{\t{o}})}} \newcommand{Ree}[]{\mathcal{Re}} \newcommand{Im}[]{\mathcal{Im}} \newcommand{deg}[1]{{#1}^{\t{o}}} \newcommand{adegg}[1]{\angle{{#1}^{\t{o}}}} \newcommand{ang}[1]{\angle{\left({#1}\right)}} \newcommand{bkt}[1]{\langle{#1}\rangle} \) \( \newcommand{\hs}[1]{\hspace{#1}} \)

  UNDER CONSTRUCTION

Python:
Functional Code




Find if key/value is in dictionary

nums = {1:"one", 2:"two", 3:"three"}
print(1 in nums)
print("three" in nums)
print(4 not in nums)
print("three" in nums.values())

>>> True 
False
True
True

# key # key # key # value


Find percentage of each character in text

dic = {}
alphabet = "abcdefghijklmnopqrstuvwxyz"
for c in alphabet:
    dic[c] = 0

with open("test.txt") as f:
    text = f.read()
doc = text.lower()

for c in doc:
    for char in alphabet:
        if c == str(char):
            dic[str(char)] += 1

for char in alphabet:
    perc = 100 * dic[char] / len(text)
    print("{0} - {1}%".format(char, round(perc,2)))

>>> a - 4.21%
b - 6.22%
c - 2.32%
...

# more chars of interest can be added, eg. '.', ' ', etc. # assign value of 0 to each dictionary key # if letter case matters, add to alphabet # count only chars in alphabet


Slice a dictionary by keys starting with a string

def slicedict(dict, start_string):
    return {k:v for k,v in dict.items() if k.startswith(start_string)}
	
dict = {'Apple': 1, 'Banana': 9, 'Carrot': 6, 'Baboon': 3, 'Duck': 8, 'Baby': 2}
print(slicedict(dict, 'Ba'))

>>> {'Banana': 9, 'Baboon': 3, 'Baby': 2}





Dragon Notes,   Est. 2018     About

By OverLordGoldDragon