Python Pandas - Kombinieren von mehreren Spalten CSV

Hallo zusammen.

Ich versuche in Python mehrere Spalten aus einer CSV-Datei zusammenzufügen und in eine neue Spalte in einer neuen CSV-Datei.

So würde mein Code aussehen:

import pandas as pd

# Load the CSV file into a Pandas DataFrame
df = pd.read_csv("Test.csv", sep=r'\\t', engine='python')

# Combine cells in a specific column using the aggregate function 'sum'
df["Name"] = df.groupby(['Name_1'])['Name_2']['Name_3'].transform('sum')

# Save the result to a new CSV file
df.to_csv("Test-new.csv", index=False)

oder evtl. auch so:

import pandas as pd

# Load the CSV file into a Pandas DataFrame
df = pd.read_csv("Test.csv", sep=r'\\t', engine='python')

# Combine cells in a specific column
df['Name'] = df[['Name_1', 'Name_2', 'Name_3']].apply(' '.join, axis=1)

# Save the result to a new CSV file
df.to_csv("Test-new.csv", index=False)

oder evtl. auch so:

import pandas as pd

# Load the CSV file into a Pandas DataFrame
df = pd.read_csv("Test.csv", sep=r'\\t', engine='python')

# Combine cells in a specific column
df["Name"] = df["Name1"] + " " + df["Name2"] + " " + df["Name3"]

# Save the result to a new CSV file
df.to_csv("Test-new.csv", index=False)

Leider funktionieren alle 3 nicht so richtig, es gibt nur Fehler.

In der CSV sind die Einträge mit TAB getrennt, so als Information.

Wisst ihr evtl. noch etwas?

Danke schonmal.

Hallo.

Stimmt, wäre hilfreich. Hier eine CSV: https://filehorst.de/d/erbwxyuJ

Also davon will ich Name_1 / Name_2 / Name_3 in ein Feld Name bekommen.

Und hier die Fehler:

Zu Code 1 folgender Fehler:

C:\Users\s.123\Downloads\python>Test.py
Traceback (most recent call last):
  File "C:\Users\s.123\Downloads\python\Test.py", line 7, in <module>
    df["Name"] = df.groupby(['Name_1'])['Name_2']['Name_3'].transform('sum')
                 ^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\s.123\AppData\Local\Programs\Python\Python311\Lib\site-packages\pandas\core\frame.py", line 8252, in groupby
    return DataFrameGroupBy(
           ^^^^^^^^^^^^^^^^^
  File "C:\Users\s.123\AppData\Local\Programs\Python\Python311\Lib\site-packages\pandas\core\groupby\groupby.py", line 931, in __init__
    grouper, exclusions, obj = get_grouper(
                               ^^^^^^^^^^^^
  File "C:\Users\s.123\AppData\Local\Programs\Python\Python311\Lib\site-packages\pandas\core\groupby\grouper.py", line 985, in get_grouper
    raise KeyError(gpr)
KeyError: 'Name_1'

Zu Code 2 folgender Fehler:

C:\Users\s.123\Downloads\python>Test3.py
Traceback (most recent call last):
  File "C:\Users\s.123\Downloads\python\Test3.py", line 7, in <module>
    df['Name'] = df[['Name_1', 'Name_2', 'Name_3']].apply(' '.join, axis=1)
                 ~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\s.123\AppData\Local\Programs\Python\Python311\Lib\site-packages\pandas\core\frame.py", line 3767, in __getitem__
    indexer = self.columns._get_indexer_strict(key, "columns")[1]
              ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\s.123\AppData\Local\Programs\Python\Python311\Lib\site-packages\pandas\core\indexes\base.py", line 5876, in _get_indexer_strict
    self._raise_if_missing(keyarr, indexer, axis_name)
  File "C:\Users\s.123\AppData\Local\Programs\Python\Python311\Lib\site-packages\pandas\core\indexes\base.py", line 5935, in _raise_if_missing
    raise KeyError(f"None of [{key}] are in the [{axis_name}]")
KeyError: "None of [Index(['Name_1', 'Name_2', 'Name_3'], dtype='object')] are in the [columns]"

Zu Code 3 folgender Fehler:

C:\Users\s.123\Downloads\python>Test2.py
Traceback (most recent call last):
  File "C:\Users\s.123\AppData\Local\Programs\Python\Python311\Lib\site-packages\pandas\core\indexes\base.py", line 3652, in get_loc
    return self._engine.get_loc(casted_key)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "pandas\_libs\index.pyx", line 147, in pandas._libs.index.IndexEngine.get_loc
  File "pandas\_libs\index.pyx", line 176, in pandas._libs.index.IndexEngine.get_loc
  File "pandas\_libs\hashtable_class_helper.pxi", line 7080, in pandas._libs.hashtable.PyObjectHashTable.get_item
  File "pandas\_libs\hashtable_class_helper.pxi", line 7088, in pandas._libs.hashtable.PyObjectHashTable.get_item
KeyError: 'Name1'

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "C:\Users\s.123\Downloads\python\Test2.py", line 7, in <module>
    df["Name"] = df["Name1"] + " " + df["Name2"] + " " + df["Name3"]
                 ~~^^^^^^^^^
  File "C:\Users\s.123\AppData\Local\Programs\Python\Python311\Lib\site-packages\pandas\core\frame.py", line 3761, in __getitem__
    indexer = self.columns.get_loc(key)
              ^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\s.123\AppData\Local\Programs\Python\Python311\Lib\site-packages\pandas\core\indexes\base.py", line 3654, in get_loc
    raise KeyError(key) from err
KeyError: 'Name1'

Hoffe das hilft.

Danke schonmal.

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