Python pandas，DataFrame常用属性，查看DataFrame的概览和统计信息

╰半夏微凉° 2022-03-18 08:44 684阅读 0赞

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**demo.py：**

# coding=utf-8
    import numpy as np
    import pandas as pd
    
    
    df1 = pd.DataFrame(np.arange(12, 24).reshape((3,4)), columns=["W","X","Y","Z"])
    print(df1)
    '''
        W   X   Y   Z
    0  12  13  14  15
    1  16  17  18  19
    2  20  21  22  23
    '''
    
    print(df1.index)  # RangeIndex(start=0, stop=3, step=1)
    print(df1.columns)  # Index(['W', 'X', 'Y', 'Z'], dtype='object')
    print(type(df1.values))  # <class 'numpy.ndarray'>
    print(df1.values)
    '''
    [[12 13 14 15]
     [16 17 18 19]
     [20 21 22 23]]
    '''
    print(df1.shape)  # (3, 4)
    print(df1.ndim)  # 2  维度
    print(df1.dtypes)  # 每一列的数据类型
    '''
    W    int64
    X    int64
    Y    int64
    Z    int64
    dtype: object
    '''
    
    print(df1.head(2))  # 显示前几行。默认前5行
    '''
        W   X   Y   Z
    0  12  13  14  15
    1  16  17  18  19
    '''
    
    print(df1.tail(2))  # 显示末尾几行。默认末尾5行
    '''
        W   X   Y   Z
    1  16  17  18  19
    2  20  21  22  23
    '''
    
    # 展示DataFrame的概览
    print(df1.info())
    '''
    <class 'pandas.core.frame.DataFrame'>
    RangeIndex: 3 entries, 0 to 2
    Data columns (total 4 columns):
    W    3 non-null int64
    X    3 non-null int64
    Y    3 non-null int64
    Z    3 non-null int64
    dtypes: int64(4)
    memory usage: 176.0 bytes
    None
    '''
    
    # 显示DataFrame的统计信息 (只能统计数值类型的列)
    print(df1.describe())  # mean均值 std标准差  50%中位数  25%四分位数
    '''
              W     X     Y     Z
    count   3.0   3.0   3.0   3.0
    mean   16.0  17.0  18.0  19.0
    std     4.0   4.0   4.0   4.0
    min    12.0  13.0  14.0  15.0
    25%    14.0  15.0  16.0  17.0
    50%    16.0  17.0  18.0  19.0
    75%    18.0  19.0  20.0  21.0
    max    20.0  21.0  22.0  23.0
    '''

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