Python Set add()用法及代碼示例

設置 add() 方法

add() 方法用於向集合中添加元素，該方法接受一個元素並將元素添加到該集合中。

注意:如果指定的元素已經存在於集合中，則該方法不會將該元素添加到集合中。

用法:

    set_name.add(element)

參數：

• element– 它表示要添加到集合中的元素。

返回值：

它不返回任何值。

範例1：

# declaring a set
cities = {"New Delhi", "Mumbai"}

# printing set before adding the element
print("cities = ", cities)

# adding new city i.e. new element
cities.add("Banglore")
cities.add("Gwalior")

# printing set after adding the elements
print("cities = ", cities)

輸出

cities =  {'New Delhi', 'Mumbai'}
cities =  {'New Delhi', 'Mumbai', 'Banglore', 'Gwalior'}

演示示例(添加集合中存在的元素)

範例2：

# declaring a set
cities = {"New Delhi", "Mumbai"}

# printing set before adding the element
print("cities = ", cities)

# adding new city i.e. new element
cities.add("Banglore")
cities.add("Gwalior")

# printing set after adding the elements
print("cities = ", cities)

# adding "Gwalior" element again
cities.add("Gwalior")

# printing set after adding the elements
print("cities = ", cities)

輸出

cities =  {'Mumbai', 'New Delhi'}
cities =  {'Gwalior', 'Mumbai', 'New Delhi', 'Banglore'}
cities =  {'Gwalior', 'Mumbai', 'New Delhi', 'Banglore'}

看到輸出，我們已經添加了元素"Gwalior"並嘗試再次添加它，但是第二次沒有添加元素"Gwalior"。