在Python中正确获取基于列标题的数据

# 错误的列标题
try:
    invalid_column = df['InvalidColumn']
except KeyError as e:
    print(f"Error: {e}")

if 'InvalidColumn' in df.columns:
    invalid_column = df['InvalidColumn']
else:
    print("Column does not exist.")

data_with_spaces = {
    'First Name': ['Alice', 'Bob', 'Charlie'],
    'Age Group': [24, 27, 22]
}
df_spaces = pd.DataFrame(data_with_spaces)

# 正确访问
first_names = df_spaces['First Name']

import pandas as pd

# 创建DataFrame
data = {
    'Name': ['Alice', 'Bob', 'Charlie'],
    'Age': [24, 27, 22],
    'City': ['New York', 'Los Angeles', 'Chicago']
}
df = pd.DataFrame(data)

# 获取单个列的数据
names = df['Name']

# 获取多个列的数据
subset = df[['Name', 'Age']]

# 检查列是否存在
if 'InvalidColumn' in df.columns:
    invalid_column = df['InvalidColumn']
else:
    print("Column does not exist.")

# 列标题包含空格的情况
data_with_spaces = {
    'First Name': ['Alice', 'Bob', 'Charlie'],
    'Age Group': [24, 27, 22]
}
df_spaces = pd.DataFrame(data_with_spaces)
first_names = df_spaces['First Name']