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--- programming:python:pandas [2022/05/29 18:50] – levor
+++ programming:python:pandas [2023/07/20 07:32] (current) – levor
@@ Line 2: / Line 2: @@
-|| command || examples || explanation / remarks ||
+| command | examples | explanation / remarks |
-| loc[] | df.loc[row_name_str, col_name_str]\\ df.loc[row_names, col_names]\\ d.loc["july", "apples"]=[5700]\\ d.loc[["january","february","march"], "apples"]=[0,0,0]  # correct example? || get or set value(s) in dataframe sub-range. Single value should be inside brackets []\\ [~link~][[https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.DataFrame.iloc.html|link]]|
+| .loc[] | df.loc[row_name_str, col_name_str]\\ df.loc[row_names, col_names]\\ d.loc["july", "apples"]=[5700]\\ d.loc{{"january","february","march"}, "apples"}=[0,0,0]  !correct example! | get or set value(s) in dataframe sub-range. Single value should be inside brackets []\\ [~link~][[https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.DataFrame.iloc.html|link]]|
 | `iloc[]` | `df.iloc[row_i, col_i]`<pp>`new_df=df.iloc[row_i1:row_i2, col_i]`<p>`new_df=df.iloc[[row_i1,row_i2,row_i3], [col_i1,col_i2]]` | get or set values in dataframe sub-range. returns a dataframe.  |
+| .columns | col_titles_list = df.columns | get list of the column titles (headers) |
 | `columns.get_loc()` | `col_i=df.columns.get_loc(col_name_s)` | get index of column by name (string) |
 | `at[]` | `df.at[row_s, col_s]` | get or set value in a **single** cell, by row and column names |
@@ Line 10: / Line 11: @@
 | drop() | new_df = df.drop('row_title_to_drop')<pp>new_df = df.drop(list_of_row_titles_to_drop)<p>new_df = df.drop(index=2)<pp>new_df = df.drop(index=[3,4,6]) | function that returns a dataframe in which the row(s) have been removed.  |
 | equals() | same_data_b = df1.equals(df2) | function that returns a boolean, True if dataframes have the same information, otherwise returns False  |
-| columns.get_loc() | example | get integer location of column, by its name |
+| columns.get_loc() | (example?) | get integer location of column, by its name |
-| index.get_loc() | example | get integer location of row, by its name |
+| index.get_loc() | (example?) | get integer location of row, by its name |
+| .sort_values(column_name) | output_df = df.sort_values(col_name)\\ output_df = df.sort_values(by=[col_name_1, col_name_2, ...], ascending=True) | sort DataFrame by given column(s)\\ NOTE: row-titles also move, so use iloc instead of loc|
 import pandas  # pip install pandas