1. 3位整数逆序
<code class="language-python">num = <a href="https://www.gaodaima.com/tag/input" title="查看更多关于input的文章" target="_blank">input</a>("请输入一个三位整数:") <a href="https://www.gaodaima.com/tag/print" title="查看更多关于print的文章" target="_blank">print</a>(num[::-1]) </code>
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2. if – else 练习
<code class="language-python">sex = input("请输入您的性别(F 或 M): ") <a href="https://www.gaodaima.com/tag/age" title="查看更多关于age的文章" target="_blank">age</a> = int(input("请输入您的年龄: ")) if sex == "M": if age < 30: print("young") elif age <= 36: print("marriageable age") else: print("old") elif sex == "F": if age < 25: print("young") elif age <= 30: print("marriageable age") else: print("old") else: print("wrong") </code>
3. if-else 和 数学计算 练习
<code class="language-python">#Python学习交流群:778463939 my_str = input("What"s the temperature? ") if my_str[-1] in ["F", "f"]: C = round((eval(my_str[0:-1]) - 32) / 1.8, 1) print(f"The converted temperature is {C}C.") elif my_str[-1] in ["C", "c"]: F = round(1.8 * eval(my_str[0:-1]) + 32, 1) print(f"The converted temperature is {F}F.") else: print("input error my dear.") </code>
4. 循环: 文件读写
<code class="language-python">with open("movie.txt") as f_in: with open("out.txt") as f_out: for line in f_in: # 假设每行数据, 分割符是 "," line_list = line.split(",") # 时长 Lasting 是最后一列 if line_list[-1] < 90: # 将该行序号写到 out.txt f_out.write(str(line_list[0])) </code>
5.循环练习: 亲密数
<code class="language-python">#Python学习交流群:778463939 x = int(input("请输入一个正整数: ")) for a in range(2, x): b = 0 for i in range(1, a): if a % i == 0: b += i r = 0 for j in range(1, b): if b % j == 0: r += j if r == a and a < b: print(a, b) </code>
6.循环: 逻辑判断
<code class="language-python">n = int(input("请输入最大兵力人数: ")) for i in range(n + 1): if (i % 3 == 2) and (i % 5 == 1) and (i % 7 == 0): print(i, end=" ") </code>
7.列表推导式
<code class="language-python">num = int(input("请输入一个 1-100 间的整数: ")) print([i for i in range(1, num + 1) if i % 2 != 0]) </code>
8.正则表达式
<code class="language-python"># 匹配: 首字母为 "数字或下划线, 其余字母为 字母,数字,下划线" import re my_str = input("请输入您将要注册的用户名: ") ret = re.match(r"[a-z_]?[a-zds_]*", my_str) print(ret.group()) print(True) if ret else print(False) </code>
9.字典按值排序
<code class="language-python">import operator int(input("输入您要处理的整数个数: ")) num_lst = list(map(int, input("请在一行输入, 两两间用 空格 隔开").split())) my_dict = {} for num in num_lst: if num not in my_dict: my_dict[num] = 1 else: my_dict[num] += 1 items = sorted(my_dict.items(), key=operator.itemgetter(1), reverse=True) for i, j in items: print(str(i) + " " + str(j)) </code>