Python在字符串中引用變量

在字符串中加入變量有三種方法：

1、+ 連字符

name = 'zhangsan'
print('my name is '+name)

#結果爲 my name is zhangsan

2、% 字符

name = 'zhangsan'
age = 25
price = 4500.225
print('my name is %s'%(name))
print('i am %d'%(age)+' years old')
print('my price is %f'%(price))
#保留指定位數小數(四捨五入)
print('my price is %.2f'%(price))

結果爲
my name is zhangsan
i am 25 years old
my price is 4500.225000
my price is 4500.23

3、format()函數

對於變量較多的情況，加入加'+'或者'%'相對比較麻煩，這種情況下可以使用format函數

name = 'zhangsan'
age = 25
price = 4500.225
info = 'my name is {my_name},i am {my_age} years old,my price is {my_price}'\
    .format(my_name=name,my_age=age,my_price=price)
print(info)

結果爲：
my name is zhangsan,i am 25 years old,my price is 4500.225