Pandas DataFrame列字符串替换未达预期问题咨询

Hey there, let's get your country name replacements working correctly! The problem here is that you're using str.replace() with a dictionary—this method doesn't support dictionary-based bulk replacements directly. Let's fix that.

The Root Cause #

df['Country'].str.replace() is designed for single string/regex pattern replacements, not mapping entire values using a dictionary. When you pass a dictionary to it, it doesn't interpret the key-value pairs as replacement rules, which is why your changes aren't showing up.

The Solution #

Use the native Pandas Series replace() method instead. This method natively supports dictionary inputs for exact-value replacements. Here's your updated code:

import pandas as pd
from pandas import ExcelWriter
from pandas import ExcelFile

pd.set_option('display.max_columns', None)
pd.set_option('display.max_rows', None)

# Load and clean the DataFrame as before
df = pd.read_excel('Energy Indicators.xls', skiprows=17, skipfooter=265-227)
df.drop(df.columns[[0,1]], axis=1, inplace=True)
df.columns=['Country', 'Energy Supply', 'Energy Supply per Capita', '% Renewable']

# Your replacement dictionary stays the same
replace_values = {
    "Republic of Korea": "South Korea",
    "United States of America": "United States",
    "United Kingdom of Great Britain and Northern Ireland": "United Kingdom",
    "China, Hong Kong Special Administrative Region": "Hong Kong"
}

# Use Series.replace() instead of str.replace()
df['Country'] = df['Country'].replace(replace_values)

# Verify the changes
print(df['Country'].head())

Why This Works #

The replace() method for Pandas Series accepts a dictionary where:

• Keys are the exact values you want to replace
• Values are the new values you want to use

It will scan the Country column and replace every exact match of the keys with their corresponding values.

Bonus: If You Need Partial Matches #

If you ever need to replace partial strings (not exact matches), you'd use str.replace() with a regex pattern, but for your use case of full country name replacements, the native replace() method is perfect.

内容的提问来源于stack exchange，提问作者vedant aher