给我说一下具体的代码实现

好的，下面是一个大致的代码实现，供您参考：

import gitlab
import pandas as pd
import numpy as np
from datetime import datetime, timedelta
from jinja2 import Environment, FileSystemLoader
import smtplib
from email.mime.text import MIMEText
from email.mime.multipart import MIMEMultipart
from email.mime.application import MIMEApplication

# GitLab API访问令牌
GITLAB_TOKEN = 'your_gitlab_token_here'

# GitLab群组ID
GROUP_ID = 'your_group_id_here'

# 查询时间范围
START_DATE = datetime.today() - timedelta(days=7)
END_DATE = datetime.today()

# 每页返回的提交数量
PER_PAGE = 100

# 邮件相关配置
SMTP_SERVER = 'your_smtp_server_here'
SMTP_PORT = 587
SMTP_USER = 'your_smtp_user_here'
SMTP_PASSWORD = 'your_smtp_password_here'
RECIPIENTS = ['recipient1@example.com', 'recipient2@example.com']

# 初始化GitLab API客户端
gl = gitlab.Gitlab('https://gitlab.com', private_token=GITLAB_TOKEN)

# 获取所有群组成员
members = gl.groups.get(GROUP_ID).members.list(all=True)

# 初始化提交历史DataFrame
commits_df = pd.DataFrame(columns=['author', 'message', 'commit_date'])

# 获取每个成员的提交历史
for member in members:
    # 获取成员的提交历史
    commits = gl.projects.get(member.id).commits.list(
        since=START_DATE, until=END_DATE, per_page=PER_PAGE)

    # 解析提交历史
    for commit in commits:
        commit_date = datetime.strptime(commit.created_at, '%Y-%m-%dT%H:%M:%S.%fZ')
        author = commit.author_name
        message = commit.message

        # 添加提交历史到DataFrame
        commits_df = commits_df.append(
            {'author': author, 'message': message, 'commit_date': commit_date},
            ignore_index=True)

# 统计每个成员的提交信息
stats_df = pd.DataFrame(columns=['author', 'commits', 'messages'])

for author in commits_df['author'].unique():
    author_commits = commits_df[commits_df['author'] == author]
    author_commits_count = len(author_commits)
    author_messages = '\n\n'.join(author_commits['message'].tolist())

    # 添加统计结果到DataFrame
    stats_df = stats_df.append(
        {'author': author, 'commits': author_commits_count, 'messages': author_messages},
        ignore_index=True)

# 生成报告
env = Environment(loader=FileSystemLoader('.'))
template = env.get_template('report_template.html')
report_html = template.render(stats_df=stats_df)

# 发送邮件
msg = MIMEMultipart()
msg['From'] = SMTP_USER
msg['To'] = ', '.join(RECIPIENTS)
msg['Subject'] = 'Weekly GitLab commits report'

msg.attach(MIMEText(report_html, 'html'))

with smtplib.SMTP(SMTP_SERVER, SMTP_PORT) as smtp:
    smtp.ehlo()
    smtp.starttls()
    smtp.login(SMTP_USER, SMTP_PASSWORD)
    smtp.sendmail(SMTP_USER, RECIPIENTS, msg.as_string())

其中，`report_template.html`是报告模板，可以使用Jinja2语法进行自定义。

这份代码的核心部分是使用GitLab API获取提交历史，并使用Pandas库进行数据处理和统计。最后使用SMTP库发送邮件。这份代码还需要您根据自己的具体情况进行适当调整。