代码示例:
import pandas as pd
df = pd.read_csv('test.csv')
print(df)
'''
打印:
userId score age
0 1 45 18
1 2 65 19
2 3 58 17
3 4 92 16
4 5 78 18
'''
'''
df.loc[] 通过标签索引获取数据
df.iloc[] 通过位置索引获取数据
'''
df.index = list("qwert")
print(df.loc['w','age']) #打印:19
print(df.loc['w'])
print(df.loc['w',:])
'''
以上两个均为打印一行,类型为Series结果如下:
userId 2
score 65
age 19
Name: w, dtype: int64
'''
print(df.loc[['w','r']])
print(df.loc[['w','r'],:])
'''
以上两个均为打印一行,类型为DataFrame,结果如下:
userId score age
w 2 65 19
r 4 92 16
'''
print(df.loc[['w','r'],['userId','score']])
'''
获取多行多列,打印:
userId score
w 2 65
r 4 92
'''
age_18 = df.loc[df['age']==18]
print(age_18)
'''
选取年龄为18岁的同学,打印:
userId score age
q 1 45 18
t 5 78 18
'''
print(age_18['score'])
'''
打印:
q 45
t 78
Name: score, dtype: int64
'''
#iloc与loc类似,取位置索引
print(df.iloc[[0,3],:])
'''
打印:
userId score age
q 1 45 18
r 4 92 16
'''import pandas as pd
df = pd.read_csv('test.csv')
print(df)
'''
打印:
userId score age
0 1 45 18
1 2 65 19
2 3 58 17
3 4 92 16
4 5 78 18
'''
'''
df.loc[] 通过标签索引获取数据
df.iloc[] 通过位置索引获取数据
'''
df.index = list("qwert")
print(df.loc['w','age']) #打印:19
print(df.loc['w'])
print(df.loc['w',:])
'''
以上两个均为打印一行,类型为Series结果如下:
userId 2
score 65
age 19
Name: w, dtype: int64
'''
print(df.loc[['w','r']])
print(df.loc[['w','r'],:])
'''
以上两个均为打印一行,类型为DataFrame,结果如下:
userId score age
w 2 65 19
r 4 92 16
'''
print(df.loc[['w','r'],['userId','score']])
'''
获取多行多列,打印:
userId score
w 2 65
r 4 92
'''
age_18 = df.loc[df['age']==18]
print(age_18)
'''
选取年龄为18岁的同学,打印:
userId score age
q 1 45 18
t 5 78 18
'''
print(age_18['score'])
'''
打印:
q 45
t 78
Name: score, dtype: int64
'''
#iloc与loc类似,取位置索引
print(df.iloc[[0,3],:])
'''
打印:
userId score age
q 1 45 18
r 4 92 16
'''