開始跟着視頻學python，第九天mark

視頻位置：138:40
字典
用大括號定義字典。{}

customer = {
    "name":"John Smith",
    "age":30,
    "is_verified":True
}
print(customer["name"])

輸出爲：

John Smith

如果是沒有的值會提示出錯。區分大小寫。

customer = {
    "name":"John Smith",
    "age":30,
    "is_verified":True
}
print(customer["Name"])   #此處N大寫了

會提示：

    print(customer["Name"])
KeyError: 'Name'

可以用get功能，防止程序報錯。

customer = {
    "name":"John Smith",
    "age":30,
    "is_verified":True
}
print(customer.get("Name"))   #此處N大寫了
print(customer.get("age"))

輸出爲：

None
30

get也可以賦值

customer = {
    "name":"John Smith",
    "age":30,
    "is_verified":True
}
print(customer.get("birthdate","Jan 1 1980"))   #沒有的會賦值
print(customer.get("age","Jan 1 1980"))    #有的不會變
print(customer)      #上面的birthdate並沒有添加進來

輸出爲：

Jan 1 1980
30
{'name': 'John Smith', 'age': 30, 'is_verified': True}

想要改變內容，可以用等號

customer = {
    "name":"John Smith",
    "age":30,
    "is_verified":True
}
customer["name"] = 'Jack Smith'
customer["birthdate"] = "Jan 1 1980"
print(customer["name"])
print(customer)

輸出爲：

Jack Smith
{'name': 'Jack Smith', 'age': 30, 'is_verified': True, 'birthdate': 'Jan 1 1980'}

小練習：
輸入一串數字如：134
輸出one two four
我的程序：

phone = {
    "0":"zero",   #注意是冒號
    "1":"one",
    "2":"two",
    "3": "three",
    "4": "four",
    "5": "five",
    "6": "six",
    "7": "seven",
    "8": "eight",
    "9": "nine",
}
user_input = input("phone: ")
for item in user_input:
    print(phone[item])

輸出爲：

phone: 148
one
four
eight

如果要用get，注意：

print(phone.get(item,"!"))  
#print(phone.get([item],"!")   這個不對，沒有中括號

視頻主的程序：

phone = {
    "0":"zero",
    "1":"one",
    "2":"two",
    "3": "three",
    "4": "four",
    "5": "five",
    "6": "six",
    "7": "seven",
    "8": "eight",
    "9": "nine",
}
user_input = input("phone: ")
output = ""
for item in user_input:
    output = output + phone.get(item,"!") + "  "
print(output)

輸出爲：

phone: 257t
two  five  seven  !  

和我的區別，視頻主把這個輸出用字符串串了起來，且加了空格，輸出爲一行。

split功能

message = input(">")
word = message.split('  ') #將字符串分割成多個單詞,分隔關鍵詞爲‘’裏面的內容
print(word)
word1 = message.split('ab') #將字符串分割成多個單詞,分隔關鍵詞爲‘’裏面的內容
print(word1)
word2 = message.split('m') #將字符串分割成多個單詞,分隔關鍵詞爲‘’裏面的內容
print(word2)

輸出爲：

>si  abde  cdmaio  king
['si', 'abde', 'cdmaio', 'king']
['si  ', 'de  cdmaio  king']
['si  abde  cd', 'aio  king']

替換某些字符串中字符

message = input(">")
words = message.split(' ') #將字符串分割成多個單詞,分隔關鍵詞爲‘’裏面的內
emojis = {
    ":)":"lalalala",
    ":(":"55555555"
}
output = ""
for word in words:
    output += emojis.get(word,word) +" "
print(output)

輸出爲：

>MY name is :(  i am happy
MY name is 55555555  i am happy 

視頻位置：150：50