def add(str1): #Alex,22,13651054608,IT with open('index',encoding='utf-8',mode='r') as f2: index = int(f2.read()) with open('staff_info',encoding='utf-8',mode='a') as f: f.write('%s,%s\n' % (str(index+1),str1)) index += 1 with open('index','w') as f3: f3.write(str(index)) def select(col,con): #col = 'name,age' con = 'age>22' dic = {'id': 0, 'name': 1, 'age': 2, 'phone': 3, 'job': 4} col_list = col.split(',') #['name', 'age'] if '>' in con: col_name,value = con.split('>') #['age', '22'] with open('staff_info',encoding='utf-8',mode='r') as f1: for line in f1: # 1,Alex,22,13651054608,IT line_lst = line.split(',') #['1', 'Alex', '22', '13651054608', 'IT'] if int(line_lst[dic[col_name]]) > int(value): if col == "*": print(line) else: for i in col_list: print(line_lst[dic[i]],end=' ') print() if '<' in con: con_lst = con.split('<') #['age', '22'] with open('staff_info',encoding='utf-8',mode='r') as f1: for line in f1: # 1,Alex,22,13651054608,IT line_lst = line.split(',') #['1', 'Alex', '22', '13651054608', 'IT'] if int(line_lst[dic[con_lst[0]]]) < int(con_lst[1]): if col == "*": print(line) else: for i in col_list: print(line_lst[dic[i]],end=' ') print() if '=' in con: con_lst = con.split('=') #['age', '22'] with open('staff_info',encoding='utf-8',mode='r') as f1: for line in f1: # 1,Alex,22,13651054608,IT line_lst = line.split(',') #['1', 'Alex', '22', '13651054608', 'IT'] if int(line_lst[dic[con_lst[0]]]) == int(con_lst[1]): if col == "*": print(line) else: for i in col_list: print(line_lst[dic[i]],end=' ') print() if 'like' in con: con_lst = con.split('like') # ['age', '22'] with open('staff_info', encoding='utf-8', mode='r') as f1: for line in f1: # 1,Alex,22,13651054608,IT line_lst = line.split(',') # ['1', 'Alex', '22', '13651054608', 'IT'] if con_lst[1] in line_lst[dic[con_lst[0]]].upper(): if col == "*": print(line) else: for i in col_list: print(line_lst[dic[i]],end=' ') print() def delet(del_num): import os with open('staff_info', encoding='utf-8', mode='r') as f1,\ open('staff_info_bak', encoding='utf-8', mode='a') as f2: for line in f1: #1,Alex,22,13651054608,IT line_list = line.split(',') if int(line_list[0]) != int(del_num): f2.write(line) else: continue os.remove('staff_info') os.rename('staff_info_bak','staff_info') def set(col,con): #age=22,name=Egon dic = {'id': 0, 'name': 1, 'age': 2, 'phone': 3, 'job': 4} col_list = col.split('=') #['age, '22'] if '>' in con: con_list = con.split('>') # ['age', '20'] import os with open('staff_info', encoding='utf-8')as f1, \ open('staff_info_bak', encoding='utf-8', mode='w') as f2: for line in f1: line_list = line.split(',') # ['1', 'Alex', '22', '13651054608', 'IT\n'] if int(line_list[dic[con_list[0]]]) > int(con_list[1]): # line_list[dic[col_list[0]]] = col_list[1] line = line.replace(line_list[dic[col_list[0]]],col_list[1]) f2.write(line) else: f2.write(line) os.remove('staff_info') os.rename('staff_info_bak','staff_info') if '<' in con: con_list = con.split('<') # ['age', '20'] import os with open('staff_info', encoding='utf-8')as f1, \ open('staff_info_bak', encoding='utf-8', mode='w') as f2: for line in f1: line_list = line.split(',') # ['1', 'Alex', '22', '13651054608', 'IT\n'] if int(line_list[dic[con_list[0]]]) < int(con_list[1]): # line_list[dic[col_list[0]]] = col_list[1] line = line.replace(line_list[dic[col_list[0]]],col_list[1]) f2.write(line) else: f2.write(line) os.remove('staff_info') os.rename('staff_info_bak','staff_info') if '=' in con: con_list = con.split('=') # ['age', '20'] import os with open('staff_info', encoding='utf-8')as f1, \ open('staff_info_bak', encoding='utf-8', mode='w') as f2: for line in f1: line_list = line.split(',') # ['1', 'Alex', '22', '13651054608', 'IT\n'] if line_list[dic[con_list[0]]] == con_list[1]: # line_list[dic[col_list[0]]] = col_list[1] line = line.replace(line_list[dic[col_list[0]]],col_list[1]) f2.write(line) else: f2.write(line) os.remove('staff_info') os.rename('staff_info_bak','staff_info') while 1: choose = input('请输入你的命令>>>').strip() choose = choose.replace(' ','') # print(choose) dic = {'id':0,'name':1,'age':2,'phone':3,'job':4} if choose == 'q': break if 'add' in choose: str1 = choose.split('add')[1] add(str1) if 'select' in choose: str1 = choose.split('select')[1] #name,agewhereage>22 col,con = str1.replace(' ','').split('where') #name,age age>22 # print(col,con) select(col,con) if 'del' in choose: del_num = choose.replace(' ','').split('del')[1] delet(del_num) if 'set' in choose: #set 列名=“新的值” where 条件 str1 = choose.split('set')[1] # set age=22 where name=Egon col, con = str1.replace(' ', '').split('where') # col:age=22,name=Egon # print(col,con) set(col,con)
精简代码后：
def add(sql): with open('index_1',encoding='utf-8') as f1: index = int(f1.read()) with open('staff_info_1',encoding='utf-8',mode='a') as f2: line = '%s,%s\n' % (index+1,sql) f2.write(line) index += 1 with open('index_1',encoding='utf-8',mode='w') as f3: f3.write(str(index)) def read_line(): with open('staff_info_1',encoding='utf-8') as f1: for line in f1: line_lst = line.strip().split(',') yield line_lst def filter(col,col_name,val,col_lst,condition): dic = {'id': 0, 'name': 1, 'age': 2, 'phone': 3, 'job': 4} for line_lst in read_line(): # ['1', 'Alex', '22', '13651054608', 'IT'] if eval(condition): if col == '*': print(','.join(line_lst)) else: for i in col_lst: print(line_lst[dic[i]], end=' ') print() def select(sql):#name, age where age>22 col,con = sql.split('where') #name,age age>22 col_lst = col.split(',') #['name', 'age'] if '>' in con: col_name, val = con.split('>') # age 22 condition = 'int(line_lst[dic[col_name]]) > int(val)' filter(col, col_name, val, col_lst, condition) elif '<' in con: col_name, val = con.split('<') # age 22 condition = 'int(line_lst[dic[col_name]]) < int(val)' filter(col, col_name, val, col_lst, condition) elif '=' in con: col_name, val = con.split('=') # age 22 condition = 'line_lst[dic[col_name]] == val' filter(col, col_name, val, col_lst, condition) elif 'like' in con: col_name, val = con.split('like') # age 22 condition = 'val in line_lst[dic[col_name]]' filter(col, col_name, val, col_lst, condition) def delet(del_name): dic = {'id': 0, 'name': 1, 'age': 2, 'phone': 3, 'job': 4} import os with open('staff_info_1',encoding='utf-8') as f,\ open('staff_info_1_bak',encoding='utf-8',mode='w') as f1: for line in f: line_lst = line.strip().split(',') if del_name in line_lst: pass else: line = ','.join(line_lst)+'\n' f1.write(line) os.remove('staff_info_1') os.rename('staff_info_1_bak','staff_info_1') def filter_set(con,col_name,val,col_lst,condition): dic = {'id': 0, 'name': 1, 'age': 2, 'phone': 3, 'job': 4} import os with open('staff_info_1', encoding='utf-8') as f, \ open('staff_info_1_bak', encoding='utf-8', mode='w') as f1: for line in f: line_lst = line.strip().split(',') if eval(condition): line = line.replace(line_lst[dic[col_lst[0]]], col_lst[1]) f1.write(line) else: f1.write(line) os.remove('staff_info_1') os.rename('staff_info_1_bak', 'staff_info_1') def set(sql):#列名=“新的值” where 条件 new,con = sql.strip().split('where') col_lst = new.split('=') if '>'in con: col_name,val = con.split('>') condition = 'int(line_lst[dic[col_name]]) > int(val)' filter_set(con, col_name, val, col_lst, condition) if '<'in con: col_name,val = con.split('<') condition = 'int(line_lst[dic[col_name]]) < int(val)' filter_set(con, col_name, val, col_lst, condition) if '='in con: col_name,val = con.split('=') condition = 'line_lst[dic[col_name]] == val' filter_set(con, col_name, val, col_lst, condition) while 1: sql = input('请输入指令>>>') if sql.lower() == 'q': break elif sql.startswith('add'): sql = sql.replace(' ','').split('add')[1] add(sql) elif sql.startswith('select'): sql = sql.replace(' ', '').split('select')[1] #name, age where age>22 select(sql) elif sql.startswith('del'): del_name = sql.replace(' ', '').split('del')[1] delet(del_name) elif sql.startswith('set'): sql = sql.replace(' ', '').split('set')[1] #列名=“新的值” where 条件 set(sql)