<add> : pd_calculate.py

- add pd_calculate script

Author: PapyrusNotes

PandasPractice/pd.py

@@ -92,4 +92,4 @@
 print('id of df2 :', id(df2))
 
 
-print(df == df2)?
+

PandasPractice/pd_calculate.py

@@ -0,0 +1,37 @@
+import pandas as pd
+
+df = pd.DataFrame([[22,'남','덕영중'], [17,'여','수리중']], index=['학생1','학생2'], columns=['age','성별','학교'])
+df2 = df.rename(columns={'age': 'age', '성별': 'gender', '학교': 'school'})
+
+
+# eq compare
+'''
+print(df == df2)   # ValueError: Can only compare identically-labeled (both index and columns) DataFrame objects
+print(df2 == df)    
+'''
+
+'''
+# drop column, row, inplace option 존재
+df.drop('학생1', inplace=True)  # 기본 axis = 0
+print(df)
+df.drop(['성별'], axis=1, inplace=True)
+print(df)
+'''
+
+# selecting data
+'''
+# selecting row
+label1 = df.loc['학생1']  # ['학생1':'학생101']
+label2 = df.loc['학생2']
+position1 = df.iloc[0]   # [3:7]
+position2 = df.iloc[1]
+print(label1)     # pandas.core.series.Series
+print(label2)
+print(position1)  # pandas.core.series.Series
+print(position2)
+print(label1 == position1)  # series끼리 eq연산을 해도 원소끼리 비교한다.
+'''
+
+# selecting column
+col1 = df['학교']
+print(col1)