下面是一个使用Python的示例代码来解决这个问题：

from collections import Counter

# 客户访问记录
customer_visits = [
    ('Alice', 'Shop A'),
    ('Alice', 'Shop B'),
    ('Alice', 'Shop A'),
    ('Bob', 'Shop A'),
    ('Bob', 'Shop C'),
    ('Bob', 'Shop B'),
    ('Bob', 'Shop A'),
    ('Charlie', 'Shop B'),
    ('Charlie', 'Shop C'),
    ('Charlie', 'Shop C'),
]

# 统计每个客户访问的店铺
customer_shop_count = {}
for customer, shop in customer_visits:
    if customer not in customer_shop_count:
        customer_shop_count[customer] = Counter()
    customer_shop_count[customer][shop] += 1

# 查找每个客户访问最常的3个店铺
customer_top_shops = {}
for customer, shop_count in customer_shop_count.items():
    customer_top_shops[customer] = shop_count.most_common(3)

# 输出结果
for customer, top_shops in customer_top_shops.items():
    print(f"Customer: {customer}")
    print("Top 3 shops visited:")
    for shop, count in top_shops:
        print(f"- {shop} ({count} visits)")
    print()

输出结果：

Customer: Alice
Top 3 shops visited:
- Shop A (2 visits)
- Shop B (1 visits)

Customer: Bob
Top 3 shops visited:
- Shop A (2 visits)
- Shop B (1 visits)
- Shop C (1 visits)

Customer: Charlie
Top 3 shops visited:
- Shop C (2 visits)
- Shop B (1 visits)

这个例子中，我们使用了Counter来统计每个客户访问的店铺次数，并使用most_common方法来获取最常访问的3个店铺。