今天我們要介紹的是python的字典,所謂的字典就是指將元素用{}包住並且元素是由一個鍵(key)配上一個值(value)所組合而成的,像是我們平常用的字典。
以下我們介紹幾個間單的字典例子。
data = {"apple":50,"banana":40,"watermelon":78,"orange":43,"grape":63}
data1 = {"a":1,
"b":2,
"d":4,
"z":26,
"k":11}
print(data)
print(data1)
首先我們先宣告字典的變數,可以使用{}來宣告。
data = {"apple":50,"banana":40,"watermelon":78,"orange":43,"grape":63}
data1 = {"a":1,
"b":2,
"d":4,
"z":26,
"k":11}
print(type(data))
print(type(data1))
可以使用type()去查詢變數的型態。
data = {"apple":50,"banana":40,"watermelon":78,"orange":43,"grape":63}
data1 = {"a":1,
"b":2,
"d":4,
"z":26,
"k":11}
for i in data:
print(i)
for j in data1:
print(j)
可以使用FOR迴圈來抓取字典裡面的key,可以看得抓出來資料是key而不是value。
data = {"apple":50,"banana":40,"watermelon":78,"orange":43,"grape":63}
data1 = {"a":1,
"b":2,
"d":4,
"z":26,
"k":11}
for i in data:
if i == "orange":
print(i)
for j in data1:
if j == "k":
print(j)
可以使用條件判斷去抓取想要的資料,但資料抓取的是key。
data = {"apple":50,"banana":40,"watermelon":78,"orange":43,"grape":63}
data1 = {"a":1,
"b":2,
"d":4,
"z":26,
"k":11}
print(data["watermelon"])
print(data1['b'])
由於字典是由一個key配一個value而如果想查詢某個key對應哪個value就可以使用上述方法去抓取value的資料。
data = {"apple":50,"banana":40,"watermelon":78,"orange":43,"grape":63}
data1 = {"a":1,
"b":2,
"d":4,
"z":26,
"k":11}
for i in data:
print(data[i])
for j in data1:
print(data1[j])
如果要用FOR迴圈查詢所有的value則可使用這種方式抓取。
data = {"apple":50,"banana":40,"watermelon":78,"orange":43,"grape":63}
data1 = {"a":1,
"b":2,
"d":4,
"z":26,
"k":11}
for i in data:
if data[i] >= 60:
print(data[i])
for j in data1:
if data1[j] >= 20:
print(data1[j])
而如果要以value做條件判斷則可以使用此種方法去做判斷。
data = {"apple":50,"banana":40,"watermelon":78,"orange":43,"grape":63}
data1 = {"a":1,
"b":2,
"d":4,
"z":26,
"k":11}
print(data)
print(data1)
data["mango"] = 90
data1["y"] = 25
print(data)
print(data1)
對字典做增加的動做只需要將變數後面加上想要加的key且key的value就可以增加進字典裡。
data = {"apple":50,"banana":40,"watermelon":78,"orange":43,"grape":63}
data1 = {"a":1,
"b":2,
"d":4,
"z":26,
"k":11}
print(data)
print(data1)
del data["apple"]
del data1["z"]
print(data)
print(data1)
如果要對字典做刪除的動作,可以使用此方法將字典裡的key跟value做刪除的動作。
data = {"apple":50,"banana":40,"watermelon":78,"orange":43,"grape":63}
data1 = {"a":1,
"b":2,
"d":4,
"z":26,
"k":11}
print(data)
print(data1)
data["apple"] = 21
data1["z"] = 16
print(data)
print(data1)
如果只是單純的修改value,可以使用此種方法將value做修改而不用刪除重新增加。
以上就是簡單的python字典的介紹,明天我們將介紹python的類別。