Pandas相关

1. Pandas数据类型Pandas数据类型几乎和Python中一样个别例外(例: ①Python: str - Pandas: object、②Python: None - Pandas: nan,NAN, NaN、③Pandas还支持category分类类型针对于分类数据操作更快更节省内存)Pandas数据类型对应的Python类型说明ObjectstrString字符串类型intint整型floatfloat浮点型datetimedatetime包中的datetime类型日期时间类型timedeltadatetime包中的timedelta类型时间差类型category无原生类型可以自定义分类类型boolbool(True False)布尔类型nan (NAN NaN)np.nan√ pd.nan❌None空值类型importpandasaspdimportnumpyasnp# 1.创建DataFrame对象dfpd.DataFrame({name:[np.nan,Tom,Mike,Jerry],age:[np.nan,18,19,21],sex:[男,女,保密,np.nan]})print(df)#2.查看df对象的详细信息print(df.info())# 3.日期类型 datetimedf2pd.DataFrame([2025-03-29,2025-03-31],dtypedatetime64[ns])print(df2)print(df2.dtypes)# 4.日期差类型 timedeltastart_datepd.to_datetime(2025-01-01)end_datepd.to_datetime(2025-03-29)print(end_date-start_date)print(type(end_date-start_date))#class pandas.Timedelta# 5.演示category类型s1pd.Series([a,b,c])print(s1)print(type(s1))#class pandas.Seriesprint(s1.dtype)#strprint(s1.dtypes)#strs12pd.Series([a,b,c],dtypecategory)print(s12)print(type(s12))#Categories (3, str): [a, b, c]print(s12.dtype)#categoryprint(s12.dtypes)#category