1、三元运算(三目运算)
#v = 前面 if 条件 else 后面 # if '条件': # v ='前面' # else : # v ='后面' # 让用户输入值,如果值是整数,则装换成整数,否则赋值为None data = input('>>>') value = int(data) if data.isdecimal() else None # 省略写法 print(value)
2、函数
'''函数的基本结构 def 函数名(): #函数内容 pass #函数的执行 函数名()''' # 1、函数计算列表 info =[11,22,33]中所有元素的和 def list_sum(a): count = 0 for i in a: count += i return count v = list_sum([11, 22, 33]) print(v) # 2、写函数,将两个列表拼接起来 def list_join(q1, q2): result = [] result.extend(q1) result.extend(q2) print(result) q = list_join([1, 2], [3, 4]) print(q) # 3、写函数,计算一个列表中有多少个数字,打印:列表中有%d个数字 # 提示:type('x') == int 判断是否是数字 def list_number(b): count = 0 for i in b: if type(i) == int: count += 1 return count list_1 = list_number(['a', 's', 'd', 1, 2, 3, ]) print('列表中有%d个数字' % (list_1,)) # 4、写函数,计算一个列表中偶数索引位置的数据构造成另一个列表,并返回 def list_even_number(arg): even = arg[2::2] return even x = list_even_number([1, 2, 3, 4, 5, 6, 7, 8, 9, ]) print(x) # 5、读取文件,将文件的内容构造成指定格式,并返回 '''a.log文件 alex|11|22 aaaa|ssss|99 目标结构: A.['alex|11|22','aaaa|ssss|99'] B.[['alex|11|22'],['aaaa|ssss|99']] C.[{'name':'alex','pwd':'11','age':'22'},{'name':'aaaa','pwd':'ssss','age':'99'}] ''' def list_a(arg): with open('a-log.txt', mode='r', encoding='utf-8') as fhl: data1 = fhl.read() data1 = data1.split() return data1 a = list_a('a') print(a) def list_b(arg): count = [] with open('a-log.txt', mode='r', encoding='utf-8') as fhl: data2 = fhl.readline() data2 = data2.split() count.append(data2) data2_1 = fhl.readline() data2_1 = data2_1.split() count.append(data2_1) return count b = list_b('b') print(b) def list_c(arg): count = {} count1 = {} content = [] with open('a-log.txt', mode='r', encoding='utf-8') as fhl: data3 = fhl.readline() data3 = data3.replace('\n', '|') data3 = str(data3) data3 = data3.split('|') data3_1 = fhl.readline() data3_1 = data3_1.split('|') val = ['name', 'pwd', 'age'] for x in range(len(val)): count[val[x]] = data3[x] content.append(count) for x in range(len(val)): count1[val[x]] = data3_1[x] content.append(count1) return content c = list_c('c') print(c)