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tutorials:python_quick_reference [2021/02/28 13:57]
marcus.williams [Multiindexing]
tutorials:python_quick_reference [2021/08/03 16:07]
marcus.williams [Data interrogation]
Line 104: Line 104:
  
 <​code>​ <​code>​
-pt_structure = pd.pivot_table(df_structure, ​\ +pt_structure = pd.pivot_table(df_structure,​ 
-    '​OBJECTID',​+    ​values='​OBJECTID',​
     index=['​propType'​],​     index=['​propType'​],​
     columns=['​strucType'​],​     columns=['​strucType'​],​
     margins=True,​     margins=True,​
-    aggfunc=len)+    aggfunc=np.sum)
 </​code>​ </​code>​
 [[http://​pandas.pydata.org/​pandas-docs/​stable/​generated/​pandas.pivot_table.html#​pandas.pivot_table|ref]] | [[http://​pandas.pydata.org/​pandas-docs/​stable/​generated/​pandas.pivot_table.html#​pandas.pivot_table|ref]] |
Line 153: Line 153:
 df_structure['​finalID'​] = np.where(df_structure.condoID.isnull(),​ df_structure['​finalID'​] = np.where(df_structure.condoID.isnull(),​
     df_structure.normalID,​ df_structure.condoID)     df_structure.normalID,​ df_structure.condoID)
 +</​code>​
 +
 +**where()**,​ **mask()**
 +Replace if condition is false and true respectively.
 +<​code>​
 +df_8.mask(df_8 > 5.0, 5.0)
 </​code>​ </​code>​
  
Line 166: Line 172:
 df.reset_index() df.reset_index()
 </​code>​ </​code>​
 +
 +Remove an unwanted level
 +<​code>​
 +df.columns = df.columns.get_level_values('​CEUDEndUse_res'​)
 +</​code>​
 +
 ===== Dropping/​deleting data ===== ===== Dropping/​deleting data =====
  
Line 408: Line 420:
 git pull origin master git pull origin master
 </​code>​ </​code>​
 +
 +===== Handy Matrix & Vector Operations =====
 +
 +**shares / norm**
 +
 +each row sums to 1
 +<​code>​
 +df_shr = df_quantity.div(df_quantity.sum(axis='​columns'​),​ axis='​index'​))
 +</​code>​
 +
 +each column sums to 1
 +<​code>​
 +df_shr = df_quantity.div(df_quantity.sum(axis='​index'​),​ axis='​columns'​))
 +</​code>  ​
 +
 +===== Jupyter Notebook Markdown Tricks ===== 
 +Links
 +<​code>​
 +[Github](http://​github.com)
 +</​code>​
 +
 +
 +Embed an image
 +<​code>​
 +![title](img/​S_res_1.png)
 +</​code>​
 +
 +===== Python Debugger (PDB) ===== 
 +[[https://​docs.python.org/​3/​library/​pdb.html|ref]]
 +
 +<​code>​
 +import pdb; pdb.set_trace()
 +</​code>​
 +
 +''​n''​ for next line; ''​c''​ to continue; ''​s''​ for step; ''​exit''​ for exit
 ===== Other functions ===== ===== Other functions =====
 ==== A ==== ==== A ====
Line 533: Line 580:
 <​code>​ <​code>​
 set([1,​2,​3]) - set([2,​3,​4]) set([1,​2,​3]) - set([2,​3,​4])
 +</​code>​
 +
 +See other set [[https://​www.w3schools.com/​python/​python_ref_set.asp|operations]] including:
 +<​code>​
 +set1.union(set2)
 +set1.intersection(set2)
 </​code>​ </​code>​
 ==== T ==== ==== T ====
tutorials/python_quick_reference.txt · Last modified: 2021/08/06 22:20 by marcus.williams