求助：使用pandas读取Excel后，如何用loc访问日期类型列名的DataFrame列

Got it, let's work through this issue. The core problem here is that pandas automatically parses your Excel column header (which was a date string like 12/31/2018) into a Timestamp (datetime64) object when reading the file. That's why using a plain string or mismatched date type with loc isn't working. Here are three straightforward solutions:

1. Use the Exact Timestamp/Datetime Object to Access the Column #

Since pandas converted the column name to a Timestamp, you can directly create a matching Timestamp or datetime object to target it:

import pandas as pd
from datetime import datetime

# Read your Excel file
df = pd.read_excel("your_file.xlsx")

# Option 1: Use pandas Timestamp
target_column = pd.Timestamp("2018-12-31")
# Option 2: Use datetime object (works too, since pandas converts it internally)
target_column = datetime(2018, 12, 31)

# Now access the column with loc
column_data = df.loc[:, target_column]

Pro tip: Run print(df.columns) first to confirm the exact Timestamp format (it might show 2018-12-31 00:00:00, but the date alone is usually enough to match).

2. Prevent Pandas from Parsing Column Headers as Dates #

If you'd rather keep the column names as plain strings (matching the original Excel format), you can read the file without letting pandas auto-parse the header dates. Here's how:

# Read the file without setting a header first
df = pd.read_excel("your_file.xlsx", header=None)
# Set the first row as column names, converting them to strings
df.columns = df.iloc[0].astype(str)
# Drop the now-redundant first row of data
df = df.iloc[1:]

# Now you can access the column using the original string name (e.g., '12/31/2018')
column_data = df.loc[:, "12/31/2018"]

This method ensures your column names stay in their original Excel string format, no automatic datetime conversion.

3. Rename the Column to a Friendly String #

If you want a more readable column name long-term, just rename it manually:

df = pd.read_excel("your_file.xlsx")

# Rename the Timestamp column to your preferred string
df.rename(columns={pd.Timestamp("2018-12-31"): "Dec_31_2018"}, inplace=True)

# Now access it with the new name
column_data = df.loc[:, "Dec_31_2018"]

Again, use print(df.columns) to double-check the exact Timestamp value you need to target in the rename dict.

内容的提问来源于stack exchange，提问作者Mohd Bilal