Zi 字媒體

8個數據清洗Python代碼，複製可用，最長11行 資料來源: https://mp.weixin.qq.com/s/iQgIhyr8XJKbqAQyu4P8rA 01.刪除多列 def drop_multiple_col(col_names_list, df) : AIM -> Drop multiple columns based on their column names INPUT -> List of column names, df OUTPUT -> updated df with dropped columns ------ df.drop(col_names_list, axis= 1 , inplace= True ) return df 02.更改數據類型 def change_dtypes(col_int, col_float, df) : AIM -> Changing dtypes to save memory INPUT -> List of column names (int, float), df OUTPUT -> updated df with smaller memory ------ df[col_int] = df[col_int].astype( int32 ) df[col_float] = df[col_float].astype( float32 ) 03.將分類變量轉換為數字變量 def convert_cat2num(df) : # Convert categorical variable to numerical variable num_encode = { col_1 : { YES : 1 , NO : 0 }, col_2 : { WON : 1 , LOSE : 0 , DRAW : 0 }} df.replace(num_encode, inplace= True ) 04.檢查缺失數據 def check_missing_data(df) : # check for any missing data in the df (display in descending order) return df.isnull().sum().sort_values(ascending= False ) 05.刪除列中的字符串 def remove_col_str(df) : # remove a portion of string in a dataframe column - col_1 df[ col_1 ].replace(, , regex= True , inplace= True ) # remove all the characters after (including ) for column - col_1 df[ col_1 ].replace( .* , , regex= True , inplace= True )   06.刪除列中的空格 def remove_col_white_space(df) : # remove white space at the beginning of string df[col] = df[col].str.lstrip()   07.用字符串連接兩列（帶條件） def concat_col_str_condition(df) : # concat 2 columns with strings if the last 3 letters of the first column are pil mask = df[ col_1 ].str.endswith( pil , na= False ) col_new = df[mask][ col_1 ] + df[mask][ col_2 ] col_new.replace( pil , , regex= True , inplace= True ) # replace the pil with emtpy space 08.轉換時間戳（從字符串到日期時間格式） def convert_str_datetime(df) : AIM -> Convert datetime(String) to datetime(format we want) INPUT -> df OUTPUT -> updated df with new datetime format ------ df.insert(loc= 2 , column= timestamp , value=pd.to_datetime(df.transdate, format= %Y-%m-%d %H:%M:%S.%f ))