Agenda¶
- 物件 (Object)
- 變數命名規則 (Variable Name Rules)
- 變數賦值 (Assignment Statements)
- 交換變數 (Swap variables)
- 資料型態 (Data Type)
- 運算子 (Operator)
- 資料型態轉換 (Data Type Conversion)
- 補充
Object¶
名稱(標籤) = 內容
a = 'Hello Python!'
In [1]:
a = 'Hello Python!'
In [2]:
print('a 物件的存放位置：', id(a))
In [3]:
a = 3
print('a 物件的存放位置：', id(a))
Variable Name Rules¶
Variable Name Rules¶
- First character
A letter (a - z, A - B) or underscore ( _ ) - Other characters
Letters (a - z, A - B) , numbers (0-9) or ( _ ) - No
: !, @, #, $, %, - etc. - Reserved words 保留字
Variable Name Rules¶
Reserved words 保留字
| False | class | finally | is | return |
| None | continue | for | lambda | try |
| True | def | from | nonlocal | while |
| and | del | global | not | with |
| as | elif | if | or | yield |
| assert | else | import | pass | |
| break | except | in | raise |
In [4]:
_variable = 1
In [5]:
variable = 1
In [6]:
first_variable = 1
In [7]:
$variable = 1
In [8]:
1variable = 1
Assignment Statements¶
In [9]:
myname = 'Kristen'
In [10]:
print('My Name : ',myname)
In [11]:
yourname = hisname = hername = 'Kristen' #Multiple Assignment
In [12]:
print('Your Name : ',yourname)
print('His Name : ',hisname)
print('Her Name : ',hername)
In [13]:
my_age, my_gender, my_city = 80, "Female", "Taipei" #Multiple Assignment
In [14]:
print('Age : ',my_age)
print('Gender : ',my_gender)
print('City : ',my_city)
Swap variables¶
Swap variables¶
In [15]:
student1_name = 'Vincent'
In [16]:
student2_name = 'Benson'
In [17]:
print('Student 1 : ',student1_name)
print('Student 2 : ',student2_name)
Swap¶
In [18]:
student1_name , student2_name = student2_name , student1_name
In [19]:
print('Student 1 : ',student1_name)
print('Student 2 : ',student2_name)
Data Type¶
| Tpye | Example |
| int | 10 |
| float | 3.14 |
| boolean | True , False |
| string | 'Apple' |
In [20]:
type(10)
Out[20]:
In [21]:
type(3.14)
Out[21]:
NOTE type( x ) : 使用 type 來得知 x 的型態
In [22]:
type('10')
Out[22]:
NOTE type( x ) : 使用 type 來得知 x 的型態
In [23]:
type(True)
Out[23]:
In [24]:
type(1>3)
Out[24]:
NOTE type( x ) : 使用 type 來得知 x 的型態
In [25]:
type(True)
Out[25]:
In [26]:
type(true)
In [27]:
type(False)
Out[27]:
In [28]:
type(false)
Operator¶
Operator¶
- 算術運算子 (Arithmetic Operator)
- 關係運算子 (Comparison Operator)
- 指派運算子 (Assignment Operator)
- 邏輯運算子 (Logical Operator)
In [29]:
print( '1 + 2 = ' ,1 + 2 )
print( '5 - 10 = ' ,5 - 10 )
print( '4 * 6 = ' ,4 * 6 )
print( '3 / 2 = ' ,3 / 2 )
print( '3 // 2 = ' ,3 // 2 )
print( '7 % 5 = ' ,7 % 5 )
Exercise¶
Q. 現在台北溫度是 19$℃$，請將$℃$ 轉成 $℉$¶
公式： $Fahrenheit = Celsius × (9/5) + 32$
Answers¶
In [30]:
Taipei_Celsius = 19
Taipei_Fahrenheit = Taipei_Celsius * (9/5) + 32
print(Taipei_Fahrenheit)
In [31]:
x = 10
In [32]:
print( 'x < 10 : ' ,x < 10 )
print( 'x > 10 : ' , x > 10 )
print( 'x <= 10 : ' ,x <= 10 )
print( 'x >= 10 : ' ,x >= 10 )
print( 'x == 10 : ' ,x == 10 )
print( 'x != 10 : ' ,x != 10 )
In [33]:
y = 10
y += 3
print(y)
In [34]:
y = 10
y -= 3
print(y)
In [35]:
y = 10
y *= 3
print(y)
In [36]:
y = 10
y /= 3
print(y)
In [37]:
y = 10
y %= 3
print(y)
In [38]:
print( 'True and True :' ,True and True )
print( 'True and False :' ,True and False )
print( 'False and True :' ,False and True )
print( 'False and False :' ,False and False )
In [39]:
print( 'True or True :' ,True or True )
print( 'True or False :' ,True or False )
print( 'False or True :' ,False or True )
print( 'False or False :' ,False or False )
Data Type II¶
Student1 = 'Emma'
Student2 = 'Sophia'
Student3 = 'Mia'
Student4 = 'Jason'
Student5 = 'Vivian'
STAT_A = ['Emma' ,'Sophia' ,'Mia' ,'Jason' ,'Vivian']
Data Type II¶
| Type | Example |
|---|---|
| list | [1,2,'YA'] |
| tuple | (1,2,'YA') |
| dictionary | {'Key1' : 'value1', 'Key2' : 'value2'} |
| set | {1,2} |
In [40]:
weather_list = [ 'Taipei' , 18.5 , 'rainy' ]
In [41]:
print( 'weather_list 的 type : ' ,type(weather_list) )
print( 'weather_list 的第一個元素 : ' ,weather_list[0] )
print( 'weather_list 的第二個元素 : ' ,weather_list[1] )
Question 取出 weather_list 中第一到第二個元素¶
In [42]:
print( 'weather_list 取出第一到第二個元素 : ' ,weather_list[0:1] )
Question 取出 weather_list 中第一到第二個元素¶
In [43]:
print( 'weather_list 取出第一到第二個元素 : ' ,weather_list[0:2] )
Question 取出 weather_list 中全部的元素¶
In [44]:
weather_list[:]
Out[44]:
In [45]:
weather_list[0:3]
Out[45]:
Note 元素 x : int , string , list , tuple
In [46]:
weather_list.append('80%') #濕度
print(weather_list)
In [47]:
weather_list.append(['Northeast',4]) #風相關[風向,風力級]
print(weather_list)
In [48]:
print('weather_list 第五個元素的資料型態是' ,type(weather_list[4]))
Note 可以加入 int , string , list , tuple
In [49]:
weather_list.extend(['Kaohsiung',25.9,'sunny','69%'])
print(weather_list)
In [50]:
weather_list.append(('Northwest',3)) #風相關[風向,風力級]
print(weather_list)
In [51]:
print(weather_list)
In [52]:
weather_list.insert(5,'Taichung')
weather_list.insert(6,21.5)
weather_list.insert(7,'cloudy')
weather_list.insert(8,'73%')
weather_list.insert(9,['North'])
print(weather_list)
Exercise¶
Q. 請將 weather_list[9] 中的 list [‘North’] 後面加入一個風力 2 級 的資訊¶
[ 'North' , 2 ]
Note
In [53]:
print('目前 weather_list 中第十個元素是 : ' ,weather_list[9] )
Answers¶
In [54]:
weather_list[9].insert(len(weather_list[9]),2)
print(weather_list)
NOTE len( ) : 使用 len 來得知 list 中的元素的數量
Exercise¶
Q. 請輸出 color_list 中第一及最後一個元素¶
In [55]:
color_list = ["Red","Green","White" ,"Black" ,"Pink"]
Answers¶
In [56]:
print( '第一個元素 : ', color_list[0])
print( '最後一個元素 : ', color_list[-1])
In [57]:
weather_tuple = ( 'Taipei' , 18.5 , 'rainy' )
In [58]:
print( 'weather_tuple 的 type : ' ,type(weather_tuple) )
print( 'weather_tuple 的第一個元素 : ' ,weather_tuple[0] )
print( 'weather_tuple 的第二個元素 : ' ,weather_tuple[1] )
In [59]:
weather_tuple.append('80%') #濕度
In [60]:
city = ('Taipei','Taichung','Kaohsiung','Taipei')
In [61]:
city.count('Taipei')
Out[61]:
city = ('Taipei','Taichung','Kaohsiung','Taipei')
In [62]:
city.index('Taichung')
Out[62]:
In [63]:
weather_set = { 'Taipei' , 18.5 , 'rainy', 18.5 }
In [64]:
print( 'weather_set 的 type : ' ,type(weather_set) )
print( 'weather_set 自動排除重複值 : ' ,weather_set)
Note
- 沒有按照原本輸入的順序擺放
- 相同的元素會被剔除
In [65]:
set1 = {1,2,3,4,6}
set2 = {2,3,4,5}
In [66]:
set1.difference( set2 )
Out[66]:
set1 = {1,2,3,4,6}
set2 = {2,3,4,5}
In [67]:
set1.symmetric_difference( set2 )
Out[67]:
set1 = {1,2,3,4,6}
set2 = {2,3,4,5}
In [68]:
set1.intersection( set2 )
Out[68]:
| Method | 說 明 |
|---|---|
| set1.intersectionset2) | set1 & set2 |
| set1.union(set2) | set1 $|$ set2 |
| set1.symmetric_difference(set2) | set1 ^ set2 |
| set1.difference(set2) | set1 $-$ set2 |
| set1.issubset(set2) | set1 $<=$ set2 |
| set1.issuperset(set2) | set1 $>=$ set2 |
Exercise¶
Q. 請找出在 color_set1 但不在 color_set2 中的顏色¶
In [69]:
color_set1 = set(["White", "Black", "Red" ,"Yellow" ,"Purple"])
color_set2 = set(["Red", "Green" ,"Yellow" ,"Orange"])
Answers¶
In [70]:
print( '在 color_set1 但不在 color_set2 的顏色 : ', color_set1.difference( color_set2 ) )
In [71]:
weather_dict = { 'Taipei':'rainy', 'Taichung':'cloudy' , 'Tainan':'sunny' , 'Kaohsiung':'sunny' , 'Kaohsiung':'rainy'}
In [72]:
print( 'weather_dict 的 type : ' ,type(weather_dict) )
print( 'weather_dict 的 Key不能重複保留後面的 : ' ,weather_dict )
Note 總共有兩個 'Kaohsiung' 的 Key ，因為 Key 不能重複，所以會留下後面的
In [73]:
weather_dict = { 'Taipei':[18.5,'rainy','80%', 'Northeast', 4], 'Taichung': [21.5, 'cloudy', '73%', 'North', 2] }
In [74]:
print(weather_dict)
Note value 也可以是一個 list
In [75]:
weather_dict['Taipei']
Out[75]:
Note 取出 weather_dict 中 Taipei 的資訊
Data Type Conversion¶
Data Type Conversion¶
| Type | 說明 |
|---|---|
| int(x) | string , float ➜ int |
| float(x) | string , int ➜ float |
| str(x) | int , float , list , tuple , dict ➜ string |
| list(x) | string , tuple, dict ➜ list |
| tuple(x) | string , list ➜ tuple |
In [76]:
int('10')
Out[76]:
In [77]:
int(3.14)
Out[77]:
In [78]:
float('10')
Out[78]:
In [79]:
float(10)
Out[79]:
In [80]:
str(10)
Out[80]:
In [81]:
str(3.14)
Out[81]:
In [82]:
str(weather_list)
Out[82]:
In [83]:
str(weather_tuple)
Out[83]:
In [84]:
str(weather_dict)
Out[84]:
In [85]:
list('10')
Out[85]:
In [86]:
list(weather_tuple)
Out[86]:
In [87]:
list(weather_dict)
Out[87]:
In [88]:
tuple('10')
Out[88]:
In [89]:
tuple(weather_list)
Out[89]:
補充¶
In [90]:
my_string = 'Hello'
my_string2 = "!!"
my_string3 = ""
my_string4 = "Hello" + my_string3 + " Python " + my_string2
my_string5 = "Hello {} !!".format("Python")
print ("my_string：", my_string)
print ("my_string2：", my_string2)
print ("my_string3：", my_string3)
print ("my_string4：", my_string4)
print ("my_string5：", my_string5)
In [91]:
print("1"+"2") #字串
print(1+2) #數值
Note 數值型的物件
In [92]:
Hi = "Hello"
In [93]:
print("Hi")
print(Hi)
Note 已經被命名的物件
In [94]:
string_format1 = "Hello {} !!".format("Kristen")
string_format2 = "Hello {:s} !!".format("Kristen")
print("string_format1 : ", string_format1)
print("string_format2 : ", string_format2)
Note 詳細介紹
In [95]:
string_format3 = 'Hello, {0:s} !! You have {1:d} error messages. Good luck, {0}.'.format('Kristen', 10000)
print("string_format3 : ", string_format3)
Note 冒號 (:) 前可以自訂變數(format裡面的內容) 的 index
In [96]:
print("--- Method 1 -----------------------------------------------------------")
print('Hello, {:s} !! You have {:d} error messages.'.format('Kristen', 10000))
print("--- Method 2 -----------------------------------------------------------")
print('Hello, {0:s} !! You have {1:d} error messages.'.format('Kristen', 10000))
print("--- Method 3 -----------------------------------------------------------")
print("Hello, %s !! You have %d error messages." %('Kristen', 10000))
In [97]:
pi = 3.14159265359
print("圓周率:%1.2f" % pi)
Note 最少要 1 個字元，取四捨五入到小數 2 位
In [98]:
print("圓周率:%6.2f" % pi)
Note 最少要 6 個字元，取四捨五入到小數 2 位 => 發現多了兩個空白
Exercise¶
Q. 創建一個 my_name 變數，並存入自己的名字，接著利用 { } 與 format 的方法，輸¶
Hello Kristen !!
Answers¶
In [99]:
my_name = "Kristen"
my_string = "Hello {} !!".format(my_name)
print(my_string)
In [100]:
print("單引號 :" ,"Hello \'Python\'")
print("雙引號 :" ,"Hello \"Python\"")
print("反斜線 :" ,"Hello \\Python\\")
print("tab :" ,"Hello \tPython")
print("換行 :" ,"Hello \nPython")
In [101]:
city = 'Taipei'
print("The 1st element of my_string = " ,city[0])
print("The 2st element of my_string = " ,city[1])
print("The last element of my_string = " ,city[-1])
In [102]:
my_string = "Hello Python"
print ("my_string 的總長度 :" ,len(my_string))
print ("'o' 總共在 my_string 中出現過幾次 :",my_string.count('a'))
In [103]:
my_list = ["Taipei", "Kaohsiung", "Taichung" ,"Keelung", "Taipei"]
print ("my_list 的總長度 :" ,len(my_list))
print ("'Taipei' 總共在 my_list 中出現過幾次 :",my_list.count('Taipei'))
In [104]:
my_string = "Hello Kristen"
print (my_string.split(" "))
In [105]:
print (my_string.split(" ")[0])
print (my_string.split(" ")[1])
Note 依照空格切割
In [106]:
my_string = "Hello Kristen !!"
my_string = my_string.replace("Kristen" ,"Rick")
print(my_string)
In [107]:
article = "North Korea is seriously examining a plan to launch a missile strike targeting an area near the US territory of Guam in response to US President Donald Trump's warning to Pyongyang that any additional threats will be met with fire and fury, according to a new statement from Gen. Kim Rak Gyom published by state-run media KCNA Thursday."
In [108]:
print (article.split(" "))
In [109]:
print ("文章中第二個字 : ",article.split(" ")[1])
In [110]:
article = "美國總統川普昨天警告北韓別再挑釁，否則將面臨「戰火與怒火」回擊。對此，白宮發言人桑德斯今天聲明，川普談話的語氣與力道，白宮國安會團隊及幕僚長凱利事先都知情。"
In [111]:
print (article)
In [112]:
article=article.replace("北韓","朝鮮民主主義人民共和國")
print (article)