import pandas as pd
import seaborn as sns

df = sns.load_dataset('titanic')
print(df.shape)
df.head()

(891, 15)

	survived	pclass	sex	age	sibsp	parch	fare	embarked	class	who	adult_male	deck	embark_town	alive	alone
0	0	3	male	22.0	1	0	7.2500	S	Third	man	True	NaN	Southampton	no	False
1	1	1	female	38.0	1	0	71.2833	C	First	woman	False	C	Cherbourg	yes	False
2	1	3	female	26.0	0	0	7.9250	S	Third	woman	False	NaN	Southampton	yes	True
3	1	1	female	35.0	1	0	53.1000	S	First	woman	False	C	Southampton	yes	False
4	0	3	male	35.0	0	0	8.0500	S	Third	man	True	NaN	Southampton	no	True

mask = (df['age'] >= 10) & (df['age'] < 20)  # 10대
mask.value_counts()  # 아이템별 개수 확인

False    789
True     102
Name: age, dtype: int64

df_teensage = df.loc[mask, :]
print(df_teensage.shape)
df_teensage.head()

(102, 15)

	survived	pclass	sex	age	sibsp	parch	fare	embarked	class	who	adult_male	deck	embark_town	alive	alone
9	1	2	female	14.0	1	0	30.0708	C	Second	child	False	NaN	Cherbourg	yes	False
14	0	3	female	14.0	0	0	7.8542	S	Third	child	False	NaN	Southampton	no	True
22	1	3	female	15.0	0	0	8.0292	Q	Third	child	False	NaN	Queenstown	yes	True
27	0	1	male	19.0	3	2	263.0000	S	First	man	True	C	Southampton	no	False
38	0	3	female	18.0	2	0	18.0000	S	Third	woman	False	NaN	Southampton	no	False