用清單取代值

使用 pandas 撰寫高效程式碼

Leonidas Souliotis

PhD Candidate

以一值取代多個值

出生年	性別	族裔	小孩名字	數量	排名
2011	FEMALE	WHITE NON HISP	HELENA	97	4

start_time = time.time()
names['Ethnicity'].loc[(names["Ethnicity"] == 'WHITE NON HISPANIC') | 
(names["Ethnicity"] == 'WHITE NON HISP')] = 'WNH'
print("Results from the above operation calculated in %s seconds" %
 (time.time() - start_time))

Results from the second method calculated in 0.0276169776917 seconds

用 .replace() 取代多個值 I

start_time = time.time()
names['Ethnicity'].replace(['WHITE NON HISPANIC','WHITE NON HISP'],
'WNH', inplace=True)
print("Time using .replace(): {} sec".format(time.time() - start_time))

Time using .replace():  0.00144791603088 sec

Difference in speed: 2160.68681809%

names['Ethnicity'].replace(['WHITE NON HISP'], 'WHITE NON HISPANIC', inplace=True)
names['Ethnicity'].replace(['BLACK NON HISP'], 'BLACK NON HISPANIC', inplace=True)

names['Ethnicity'].replace(['BLACK NON HISP','WHITE NON HISP'], ['BLACK NON HISPANIC',
'WHITE NON HISPANIC'], inplace=True)

一起來練習吧！

使用 pandas 撰寫高效程式碼