在pandas df中查找给定列的第一个occure

import pandas as pd

# 创建一个示例DataFrame
data = {'Name': ['John', 'Alice', 'Bob', 'Alice'],
        'Age': [25, 28, 30, 35],
        'City': ['New York', 'Paris', 'London', 'Paris']}
df = pd.DataFrame(data)

# 查找给定列的第一个occurrence
column_name = 'Name'
value = 'Alice'
first_occurrence = df.loc[df[column_name] == value].index[0]

print(f"The first occurrence of '{value}' in column '{column_name}' is at index {first_occurrence}.")

The first occurrence of 'Alice' in column 'Name' is at index 1.