Differences

This shows you the differences between two versions of the page.

--- pandas_dataframe [2023/07/21 22:16] – [Create a dataframe from list of lists] raju
+++ pandas_dataframe [2023/09/07 21:45] (current) – [lookup value] raju
@@ Line 283: / Line 283: @@
 tags | uses [http://pandas.pydata.org/pandas-docs/stable/generated/pandas.Series.str.split.html pandas.Series.str.split]
+==== lookup value ====
+To pick the first value in column 'A' for rows where column B is FOO
+<code>
+df.loc[df['B'] == 'FOO', 'A'].iloc[0]
+</code>
+Example:
+<code>
+$ ipython
+In [1]:
+import pandas as pd
+df = pd.DataFrame({'A': ['p1', 'p2', 'p3', 'p4'], 'B': [1, 3, 3, 2]})
+print(df)
+    A  B
+  p1  1
+  p2  3
+  p3  3
+  p4  2
+In [2]:
+df.loc[df['B'] == 3, 'A']
+Out[2]:
+    p2
+    p3
+Name: A, dtype: object
+In [3]:
+df.loc[df['B'] == 3, 'A'].iloc[0]
+Out[3]:
+'p2'
+</code>
+search tags | value of one column when another column equals something
+Ref:- https://stackoverflow.com/questions/36684013/extract-column-value-based-on-another-column-in-pandas
 ===== Series related =====