Replace values using lists

Writing Efficient Code with pandas

Leonidas Souliotis

PhD Candidate

Replace multiple values with one value

Year of Birth	Gender	Ethnicity	Child's First Name	Count	Rank
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

Replace multiple values using .replace() 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)

Let's do it

Writing Efficient Code with pandas