学習ノート-pandas:データ構造の基本知識


Series
  • 初認識Series
  • # -*- coding: utf-8 -*-
    
    import pandas as pd
    
    """
         Series(     index)
    """
    s1 = pd.Series([1,2,3,4])
    print(s1)
    
    """
       index
    """
    s2 = pd.Series([1,2,3,4], index=['a','b','c','d'])
    print(s2)
    
    """
    Series     
    """
    #     (  )
    print(s2.index)
    #    
    print(s2.values)
    
    0    1
    1    2
    2    3
    3    4
    dtype: int64
    a    1
    b    2
    c    3
    d    4
    dtype: int64
    Index(['a', 'b', 'c', 'd'], dtype='object')
    [1 2 3 4]
    
  • 操作Series
  • # -*- coding: utf-8 -*-
    
    import pandas as pd
    
    """
        
    """
    s1 = pd.Series([1,2,3,4])
    s2 = pd.Series([1,2,3,4], index=['a','b','c','d'])
    
    #  
    """
    (1)      
    """
    #       
    print(s2['a'])
    #       (Series   )
    print(s2['a':'d'])
    #       (   )
    print(s2[['a','c']])
    """
    (2)      
    """
    print(s2[0])
    #             
    
    #  
    a = pd.Series([5],index=['e'])
    s2 = s2.append(a)
    print(s2)
    
    b = pd.Series([5,6],index=['e1','e2'])
    s2 = s2.append(b)
    print(s2)
    
    #   
    s2 = s2.drop('e1')
    print(s2)
    """
            Series 
    """
    print('a' != s2.values)
    
    #  
    s2['e2'] = 22
    print(s2)
    """
        
    """
    s2[['b','c']] = 333
    s2[['a','d']] = [111,99]
    print(s2)
    
    #   Series(    )
    dic1 = {"Tom":12,"Alice":11,"Bob":22}
    s3 = pd.Series(dic1)
    print(s3)
    
    #     
    s2.index = range(0,len(s2))
    print(s2)
    

    DataFrame
  • 初認識dataFrame
  • # -*- coding: utf-8 -*-
    
    import pandas as pd
    
    df1 = pd.DataFrame({"age":[1,2,3,4,5],"name":['a','b','c','d','e']}, 
                        index=['s1','s2','s3','s4','s5'])
    print(df1)
    
    """
    Dataframe  
    """
    #   
    print(df1.index)
    #   
    print(df1.columns)
    #  
    print(df1.values)
    
        age name
    s1    1    a
    s2    2    b
    s3    3    c
    s4    4    d
    s5    5    e
    Index(['s1', 's2', 's3', 's4', 's5'], dtype='object')
    Index(['age', 'name'], dtype='object')
    [[1 'a']
     [2 'b']
     [3 'c']
     [4 'd']
     [5 'e']]
    
  • 簡単操作dataFrame
  • import pandas as pd
    
    df1 = pd.DataFrame({"age":[1,2,3,4,5],"name":['a','b','c','d','e']}, 
                        index=['s1','s2','s3','s4','s5'])
    """
        
    """
    #df1.columns = range(0,len(df1.columns))
    #print(df1)
    """
          
    """
    df1.rename(columns = {"age":"  ","name":"  "}, inplace=True)
    print(df1)
    
    """
        
    """
    df1.index = range(0,len(df1.index))
    
    """
        
    """
    #        
    df1["rank"] = [1,2,4,3,5]
    print(df1)
    #          
    df1.insert(0,'number',[101,102,103,104,105])
    print(df1)