python全栈开发中级班全程笔记（第二模块、第三章）（员工信息增删改查作业讲解）

python全栈开发中级班全程笔记

第三章：员工信息增删改查作业代码

作业要求：

员工增删改查表
用代码实现一个简单的员工信息增删改查表
需求：

1、支持模糊查询，
（1、find name ,age form staff_table where age > 22
(查找 staff_fable （文件）内所有 age > 22 的name 和 age全部打印）
（2、find * from staff_table where dept = "IT"
(查找所有部门是 IT的所有列打印出来*代表所有)
（3、find * from staff_table where enroll_date like "2013"
(查找所有 enroll_date (登记日期）为 2013的序列并打印)

2、可创建员工信息记录，以 phone 做唯一键（既不允许表内有手机号重复的情况），staff_id 需自增
语法格式为：add staff Alex Li,25,134435344,IT,2015-10-29

3、可删除指定员工信息记录，输入员工id 即可删除
语法格式：del staff 3

4、可修改员工信息 语法如下：
UPDATE staff_table SET dept = "Market" WHERE dept =  "IT"(把部门是 IT 的全部更改成 Market）
UPDATE staff_table SET age = 25 WHERE name =  "Alex Li" (把 name = Alex Li 的年龄改成 25 )
以上每条语句执行完毕后，要显示影响了多少条记录，（比如查询，要显示查询出多少条、修改要显示修改多少条

整体思路图：

代码奉上：

# -*- coding:utf-8 -*-
from tabulate import tabulate
import os

FILE_NAME = "staff_table"
OPTION = ["id", "name", "age", "phone", "dept", "enroll_date"]

# 加载员工信息表并转成指定格式
def info(file_name):
    data = {}
    for i in OPTION:
        data[i] = []
    with open(file_name, "r", encoding="utf-8") as f:
        for line in f:
            staff_id, name, age, phone, dept, enroll_date = line.strip().split(",")
            data["id"].append(staff_id)
            data["name"].append(name)
            data["age"].append(age)
            data["phone"].append(phone)
            data["dept"].append(dept)
            data["enroll_date"].append(enroll_date)
        return data

INFO_DATA = info(FILE_NAME)    # 程序启动后就执行

# 把修改的数据写入硬盘
def write_info():
    f = open("%s" % FILE_NAME, "w", encoding="utf-8")
    for index, staff_tb in enumerate(INFO_DATA["id"]):
        res = []
        for col in OPTION:
            res.append(INFO_DATA[col][index])
        f.write(",".join(res)+"\n")

# 报错字体颜色
def print_log(calc, log_type = "info"):
    if log_type == "info":
        print("\033[33;1m%s\033[0m" % calc)
    elif log_type == "error":
        print("\033[31;1m%s\033[0m" % calc)

# 自动删除函数
def del_info(del_name, del_term):
    for index, del_loop in enumerate(INFO_DATA[del_name]):
        if del_loop == del_term:
            for del_key in OPTION:
                del INFO_DATA[del_key][index]
                write_info()
                return
    else:
        print_log("没有此序号或未检测到关键字[id=NO.]", "error")

# 解析条件并返回值
def less(field, term):
    result = []
    for index, cont in enumerate(INFO_DATA[field]):
        if float(cont) > float(term):
            whole_article = []
            for cont_name in OPTION:
                whole_article.append(INFO_DATA[cont_name][index])
            result.append(whole_article)
    return result

def greater(field, term):
    result = []
    for index, cont in enumerate(INFO_DATA[field]):
        if float(cont) < float(term):
            whole_article = []
            for cont_name in OPTION:
                whole_article.append(INFO_DATA[cont_name][index])
            result.append(whole_article)
    return result

def equal(field, term):
    result = []
    for index, cont in enumerate(INFO_DATA[field]):
        if cont == term:
            whole_article = []
            for cont_name in OPTION:
                whole_article.append(INFO_DATA[cont_name][index])
            result.append(whole_article)
    return result

def like(field, term):
    result = []
    for index, cont in enumerate(INFO_DATA[field]):
        if term in cont:
            whole_article = []
            for cont_name in OPTION:
                whole_article.append(INFO_DATA[cont_name][index])
            result.append(whole_article)
    return result

# 解析 where 条件并过滤数据
def syntax_where(offside):
    handle = {">": less,
              "<": greater,
              "=": equal,
               "like": like
              }
    for _key, func in handle.items():
        if _key in offside:
            field, term = offside.split(_key)
            match_result = func(field.strip(), term.strip())
            return match_result
    else:
        print_log("语法错误：where条件只支持[>,<,=,where]", "error")

# 解析 find 语句并返回结果
def syntax_find(content, condition):
    find_name = condition.split("from")[0].split("find")[1].split(",")
    find_name = [i.strip() for i in find_name]
    if "*" in find_name[0]:
        print(tabulate(content, headers=INFO_DATA, tablefmt="grid"))
    else:
        title_list = []
        for title in content:
            item_list = []
            for item in find_name:
                item_index = OPTION.index(item)
                item_list.append(title[item_index])
            title_list.append(item_list)
        print(tabulate(title_list, headers=find_name, tablefmt="grid"))
    print_log("成功查询到%s条数据" % len(content), "info")

# 增加条目函数
def syntax_add(content, codition):
    codition = codition.split("staff_table")[1].split(",")
    if codition[2] in INFO_DATA["phone"]:
        print_log("手机号码重复", "error")
    else:
        id_id = []
        for add_id in INFO_DATA["id"]:
            id_id.append(int(add_id))
        codition.insert(0, (id_id[-1] + 1))
        for last_name, last_info in zip(OPTION, codition):
            INFO_DATA[last_name].append(str(last_info))
        write_info()
        print_log("成功增加第%s条数据" % int(len(content)+1), "info")

# 删除条目函数
def syntax_del(content, codition):
    codition = [i.strip() for i in codition.split(" ")]
    if "id" in codition[3]:
        if "id" in codition[-1]:
            del_name, del_term = codition[-1].split("=")
            del_info(del_name, del_term)
        elif "id" in codition[3]:
            del_name = codition[-3]
            del_term = codition[-1]
            del_info(del_name, del_term)
            print_log("成功删除第%s条数据" % del_term, "info")
        else:
            print_log("没有此序号或未检测到关键字[id=NO.]", "error")
    elif "id"not in codition and len(content) > 0:
        del_info(del_name="id", del_term=content[0][0])
        print_log("成功删除第%s条数据" % content[0][0], "info")
    else:
        print_log("没有此序号或未检测到关键字[id=NO.]", "error")

# 修改的函数
def syntax_update(content, codition):
    codition = codition.split("set")
    if len(codition) > 1:
        index_own, number = codition[1].strip().split("=")
        for index_value in content:
            ind_index = index_value[0]
            ind_index_id = INFO_DATA['id'].index(ind_index)
            INFO_DATA[index_own.strip()][ind_index_id] = number.strip()
        write_info()            # 修改后的数据写进文件
        print_log("成功修改%s条数据" % len(content), "info")
    else:
        print_log("语法格式错误，不存在 set 关键词", "error")

# 解析语句并执行
def syntax_parser(order):
    syntax_dict = {
                    "find": syntax_find,
                    "add": syntax_add,
                    "del": syntax_del,
                    "update": syntax_update
                    }
    if order.split(" ")[0] in ("find", "add", "del", "update"):
        if "where" in order:
            left_side, offside = order.split("where")
            final_result = syntax_where(offside)
        else:
            final_result = []
            for index, info_id in enumerate(INFO_DATA["id"]):
                info_set = []
                for i in OPTION:
                    info_set.append(INFO_DATA[i][index])
                final_result.append(info_set)
            left_side = order
        order_start = order.split()[0]
        if order_start in syntax_dict:
            syntax_dict[order_start](final_result, left_side)
    else:
        print_log("语法错误!\n[find/ add/ del/ update [size] from [staff_table] where [term][>,<,=,like][parameter]\n", "error")

# 让用户输入语句并执行！
def main():
    while True:
        order = input("staff_db:"). strip()
        if not order: continue
        syntax_parser(order)
main()