问题使用Dataframe中的现有列分配列值

我正在尝试在数据框中创建一个新列，该列根据另一列中的值分配值。我正在使用的代码分配值，但不是我想要的。
代码示例如下：

#define track styles
short = [4,6,8,9,11,20,24,28,30,33,35]
inter = [2,3,7,12,13,17,19,25,27,32,34,36]
long = [5,14,15,21,23,26]
plate = [1,10,18,31]
road = [16,22,29]

#input driver and stat info
driver1 = input('Choose driver: ')

#read driver data to dataframe
df = pd.read_csv(driver1 + '_2018.csv')

#add track type
df['Type'] = ''

for i in range(len(df)):

if df['Race'][i] in short:
    df['Type'][i] = 'short'
elif df['Race'][i] in inter:
    df['Type'] = 'intermediate'
elif df['Race'][i] in long:
    df['Type'] = 'long'
elif df['Race'][i] in plate:
    df['Type'] = 'plate'
else:
    df['Type'] = 'road'

print(df.head())
我得到以下输出：

C:EclipseWorkspacecsse120PersonalNASCAR_ProjectsOtherdriver_review.py:45: SettingWithCopyWarning:
A value is trying to be set on a copy of a slice from a DataFrame

See the caveats in the documentation: http://pandas.pydata.org/pandas-docs/stable/indexing.html#indexing-view-versus-copy
df'Type' = 'short'
Race Start Mid Race ... Total Laps DRIVER RATING Type
0 1 5 23 ... 207 105.2 intermediate
1 2 16 7 ... 325 94.2 intermediate
2 3 10 2 ... 267 106.1 intermediate
3 4 5 11 ... 311 80.0 intermediate
4 5 6 3 ... 200 113.0 intermediate

[5 rows x 20 columns]
请注意，'Type'列将返回所有'intermediate'，它应包括['plate'，'intermediate'，'intermediate'，'short'，'long']。