03 ,pd 基础 : dataframe,df 创建,Series =》Dataframe,加行,加列

    技术2023-09-17  79

    1 ,创建 df ,字典创建 :pd.DataFrame(dict)

    代码 : if __name__ == '__main__': dict = {"name":["wtt","dfl","xiaoya"],"age":[29,32,3]} df01 = pd.DataFrame(dict) print(df01) ============================== age name 0 29 wtt 1 32 dfl 2 3 xiaoya

    2 ,创建空 df :pd.DataFrame(columns=[“name”,“sex”])

    代码 : 创建空的 df df01 = pd.DataFrame(columns=["name","sex","age","addr"]) print(df01) ============================ Columns: [name, sex, age, addr] Index: []

    3 ,sr =》df ,加列 : df01[“name”] = sr_name

    思路 : 1 ,df : 创建空 df ,无数据,有列名 2 ,sr : 创建两个 Series代码 : if __name__ == '__main__': # 创建空 df : df01 = pd.DataFrame(columns=["name","sex","age"]) # 创建 Series : sr_name = pd.Series(["a","b","c","d","e"]) sr_sex = pd.Series(["m","m","w","w","m"]) sr_age = pd.Series([7,9,5,8,6]) # 组装 : df01["name"] = sr_name df01["sex"] = sr_sex df01["age"] = sr_age # 打印 : print(df01) ============================= name sex age 0 a m 7 1 b m 9 2 c w 5 3 d w 8 4 e m 6

    4 ,sr =》df ,加行 : df.append(df01,ignore_index=True)

    不建议使用 :因为他产生了新的对象代码 : if __name__ == '__main__': # 创建空 df : df = pd.DataFrame(columns=["name","sex","age"]) # 创建 Series : sr01 = pd.Series(["a","w",18]) sr02 = pd.Series(["b","m",20]) sr03 = pd.Series(["c","w",16]) # 创建三个子 df df01 = sr01.to_frame().T df01.columns = ["name","sex","age"] df02 = sr02.to_frame().T df02.columns = ["name","sex","age"] df03 = sr03.to_frame().T df03.columns = ["name","sex","age"] df = df.append(df01,ignore_index=True) df = df.append(df02,ignore_index=True) df = df.append(df03,ignore_index=True) print(df) =============================== name sex age 0 a w 18 1 b m 20 2 c w 16
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