黃芝晴的軟體工程師之路

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黃芝晴 / Hedi Huang

python

input, output, conditional branching, math, exception handling, looping, functions

終端機開啟python

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REPL

Read-Eval-Print Loop

讀取求值輸出循環

help()

look for every element in python

>>> help(str)

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print()

>>> health = "water and good foods"

>>> print("health is" + health)

health iswater and good foods

>>> print("health is" , health)

health is water and good foods

如果要 print 的內容有換行

可以分成多個print來執行

print("I " + verb + " everyday.\n" + noun.capitalize() + " is my favorite.\nIt make me feel " + adjective + ".")

↓

print("I " + verb + " everyday.")

print(noun.capitalize() + " is my favorite.")

print("It make me feel " + adjective + ".")

input()

>>> favorite_color = input("What is your favorite color? ")

>>> print(favorite_color + " is a good color.")

What is your favorite color? blue

blue is a good color.

data type

int(integer)

float

str(string)

literal

Literals 提供值給變數，再根據變數為賦予他們資料型態

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round()

to the closest integer

ex.

>>> round(5.551115123125783e-17)

>>> round(11.9)

>>> round(”11.9”)

int()

to the closest integer which is under the number

>>> int(11.9)

>>> int(”11.9”)

float()

>>> float(11)

11.0

>>> float(”11”)

11.0

str()

>>> str(24)

'24'

operation

order(PEMDAS)

PEMDAS_Please Excuse My Dear Aunt Sally

PEMDAS_

Parenthesis(小括號)

Exponent(指數)

Multiplication(乘)

Division(除)

Addition(加)

subtraction(減)

sequence

string—>immutable

to print

>>> print(”I can’t.\nJust can’t.”)

I can't

Just can't

>>> print("""She said,

... "I can't,

... Just can't." """)

She said,

"I can't,

Just can't."

#if use """ (triple quotes), just press enter, \n is no need

>>> print("""She said,\n"I can't." """)

She said,

"I can't."

>>> health = "water" + " and good food" + "!" * 3

>>> health += " Isn't it?"

>>> print(health)

water and good food!!!

#there are no -= if wanting doing subtraction, just assign again.

#str is immutable(不可變)

to len

>>> len("Hedi Huang")

# space is included.

>>> name = input("name: ")

name: Hedi Huang

>>> len(name)

method

method is a function that is owned by an object. You can access these by using dot notation.

.upper() & .lower()

>>> name.upper()

'HEDI HUANG'

>>> name

'Hedi Huang'

>>> print(name.upper())

HEDI HUANG

>>> name.lower()

'hedi huang'

index(for string!)

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booleans

>>> bool(0)

False

>>> bool(1)

True

>>> bool("")

False

>>> bool(not(0 and 1))

True

>>> "he" in "hedi"

>>> true

>>> list = ["hedi, hide"]

>>> "hedi" in list

>>> true

#If there is a value, then it's True.

#Otherwise, it's False.

#Only all are true is true.

comparison

>>> "hedi">"tina"

False

>>> "four">"one"

False

#compare the order of the words' first alphabet

#the later order is bigger

>>> "cosmos" != "cosmos"

False

# != not the same

list—>mutable

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.append & .extend

>>> temperature = []

>>> temperature.append(36.5)

>>> temperature.append(36.8)

>>> temperature

[36.5, 36.8]

>>> er_temperature = [39, 40, 38]

>>> temperature.extend(er_temperature)

>>> temperature

[36.5, 36.8, 39, 40, 38]

#append => 在集合a裡新增項目

#extend => 在集合a裡加進集合b 故集合a的內容已變更，集合b內容不變

index(for list!)

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list裡的variable也是可以直接assign的

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.insert

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↑讓list裡的第1個index的值是41

del & .pop(LIFO Last In First Out)

但其實都是從list裡刪掉不過.pop可以不指定，還可以暫存

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>>> er_temperature

[39, 36]

>>> store = er_temperature.pop()

>>> store

.split() ft. time.sleep()

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ft. time.sleep()

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.split() turns string into list

you can import time and use time.sleep() on your print

.join()

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loop

.copy

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del & .pop(LIFO Last In First Out)

.split() ft. time.sleep()

multidimensional list(lists inside lists / rows and columns)

sum()

tuples(immutable_list, more memory efficient than list)

sequence operation(method)

sequence method

dictionary

accessing key & value

.keys()

.values()

sorted()

update & mutate dictionary

iterate over dictionary

.items()

packing(for dictionary)

unpacking(for dictionary)

constants

function

parameter & argument (send to function)(vs return)

the time to create function:

= vs ==

scope

return (from function) (vs parameter & argument)

range(start, stop, step)

factor & common factor_intersection

while loop(co→sys.exit)

OOP(Object-Oriented Programming)

python object

instantiate(instance)

wiki_date(application of strftime & strptime)

timezone

note

Build an Application

think about user story(design function) 至少要有HELP、DONE、SHOW

write “show_help def” and show it to user at the beginning of this script

Want to print your doc?
This is not the way.

Try clicking the ⋯ next to your doc name or using a keyboard shortcut (

CtrlP

) instead.