pandas DataFrame的属性和信息概览

代码示例:

import pandas as pd

df1 = pd.read_csv('test.csv')
print(df1)
'''
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
'''
print(df1.shape)    #获取行和列,打印(5, 3)
print(df1.index.to_list())    #获取行索引,打印[0, 1, 2, 3, 4]
print(df1.columns.to_list())    #获取列索引,打印['userId', 'score', 'age']
print(df1.ndim)    #获取数据的维度,打印2
print(df1.values)
'''
values属性也会以二维ndarray的形式返回DataFrame的数据
打印:
[[ 1 45 18]
 [ 2 65 19]
 [ 3 58 17]
 [ 4 92 16]
 [ 5 78 18]]
'''
print(df1.info())
'''
展示df的概览信息
打印:
<class 'pandas.core.frame.DataFrame'>
RangeIndex: 5 entries, 0 to 4
Data columns (total 3 columns):
userId    5 non-null int64
score     5 non-null int64
age       5 non-null int64
dtypes: int64(3)
memory usage: 200.0 bytes
None
'''
print(df1.head(3))
'''
展示头几行,默认显示5行
打印:   
    userId  score  age
0       1     45   18
1       2     65   19
2       3     58   17
'''
print(df1.tail(2))
'''
展示尾几行,默认显示5行
打印:
   userId  score  age
3       4     92   16
4       5     78   18
'''