Знакомство с pandas

from pandas import read_csv
df1 = read_csv("df1.txt")
print(df1)
print(df1.values)
print()
 
     x y
0  427 3
1  707 4
2  957 2
3  437 1
[['427 3']
 ['707 4']
 ['957 2']
 ['437 1']]

print(df1.min())
print(df1.max())
print()
print(df1.mean())
 
print(df1.mean(axis=0)['x'])
print(df1.values.mean(axis=0))
x y    427 3
dtype: object
x y    957 2
dtype: object
 
Series([], dtype: float64)
---------------------------------------------------------------------------
 
KeyError                                  Traceback (most recent call last)
 
c:\users\stark\desktop\jupyter\venv\lib\site-packages\pandas\core\indexes\base.py in get_loc(self, key, method, tolerance)
   3079             try:
-> 3080                 return self._engine.get_loc(casted_key)
   3081             except KeyError as err:
 
pandas\_libs\index.pyx in pandas._libs.index.IndexEngine.get_loc()
 
pandas\_libs\index.pyx in pandas._libs.index.IndexEngine.get_loc()
 
pandas\_libs\hashtable_class_helper.pxi in pandas._libs.hashtable.PyObjectHashTable.get_item()
 
pandas\_libs\hashtable_class_helper.pxi in pandas._libs.hashtable.PyObjectHashTable.get_item()
 
KeyError: 'x'
 
 
The above exception was the direct cause of the following exception:
 
KeyError                                  Traceback (most recent call last)
 
<ipython-input-9-2e63fd2404d7> in <module>
      5 dfs = [df1]
      6 pd.concat(dfs, axis=1).mean(axis=1)
----> 7 print(df1.mean(axis=0)['x'])
      8 print(df1.values.mean(axis=0))
 
c:\users\stark\desktop\jupyter\venv\lib\site-packages\pandas\core\series.py in __getitem__(self, key)
    851 
    852         elif key_is_scalar:
--> 853             return self._get_value(key)
    854 
    855         if is_hashable(key):
 
c:\users\stark\desktop\jupyter\venv\lib\site-packages\pandas\core\series.py in _get_value(self, label, takeable)
    959 
    960         # Similar to Index.get_value, but we do not fall back to positional
--> 961         loc = self.index.get_loc(label)
    962         return self.index._get_values_for_loc(self, loc, label)
    963 
 
c:\users\stark\desktop\jupyter\venv\lib\site-packages\pandas\core\indexes\base.py in get_loc(self, key, method, tolerance)
   3080                 return self._engine.get_loc(casted_key)
   3081             except KeyError as err:
-> 3082                 raise KeyError(key) from err
   3083 
   3084         if tolerance is not None:
 
KeyError: 'x'

df["x"].mean() или df.x.mean()

df.x.std()

df.x.max() df.x.min ()

df1=pd.DataFrame( {'x':[427,707,957,437],'y':[3,4,2,1]})
print(df1)
df1["x"].mean()

     x  y
0  427  3
1  707  4
2  957  2
3  437  1
Out[80]: 632.0

math.sqrt((df1.x**2).sum()/len(df1))

np.sqrt ((df1.x**2).mean())