第1题：输出1–20之间的奇数
Task: Print all odd numbers from 1 to 20, separated by spaces.
示例 / Example Output:
1 3 5 7 9 11 13 15 17 19答案 / Answer:
for i in range(1, 21):
if i % 2 != 0:
print(i, end=" ")第2题：输出1–20之间的偶数
Task: Print all even numbers from 1 to 20, separated by spaces.
示例 / Example Output:
2 4 6 8 10 12 14 16 18 20答案 / Answer:
for i in range(1, 21):
if i % 2 == 0:
print(i, end=" ")第3题：计算列表中所有数字的总和
Task: Create a function sum_list(nums) that returns the sum of all elements in a list.
示例 / Example:
输入 Input: [5, 10, 15]
输出 Output: 30答案 / Answer:
def sum_list(nums):
total = 0
for n in nums:
total += n
return total
print(sum_list([5, 10, 15]))第4题：合并两个列表
Task: Combine two lists [1, 2, 3] and [4, 5, 6] into a new list.
输出 / Output:
[1, 2, 3, 4, 5, 6]答案 / Answer:
list1 = [1, 2, 3]
list2 = [4, 5, 6]
combined = list1 + list2
print(combined)第5题：提取列表中的奇数元素
Task: Write a function that returns a new list containing only the odd numbers.
示例 / Example:
输入 Input: [1, 4, 7, 10, 13]
输出 Output: [1, 7, 13]答案 / Answer:
def odd_elements(lst):
result = []
for n in lst:
if n % 2 != 0:
result.append(n)
return result
print(odd_elements([1, 4, 7, 10, 13]))第6题：拼接字符串列表
Task: Combine the list ["Python", "is", "fun"] into a single sentence.
输出 / Output:
Python is fun答案 / Answer:
words = ["Python", "is", "fun"]
sentence = " ".join(words)
print(sentence)第7题：反转每个单词
Task: Write a function reverse_words(words) that reverses each string in a list.
示例 / Example:
输入 Input: ["apple", "banana", "orange"]
输出 Output: ["elppa", "ananab", "egnaro"]答案 / Answer:
def reverse_words(words):
return [w[::-1] for w in words]
print(reverse_words(["apple", "banana", "orange"]))第8题：计算列表元素总和
Task: Given [4, 7, 11, 3], print the total sum of numbers.
输出 / Output:
Total: 25答案 / Answer:
numbers = [4, 7, 11, 3]
print("Total:", sum(numbers))第9题：偶数翻倍
Task: Write a function that doubles all even numbers, keeping odd numbers unchanged.
示例 / Example:
输入 Input: [2, 5, 8, 3]
输出 Output: [4, 5, 16, 3]答案 / Answer:
def double_evens(nums):
result = []
for n in nums:
if n % 2 == 0:
result.append(n * 2)
else:
result.append(n)
return result
print(double_evens([2, 5, 8, 3]))第10题：统计每个单词中的元音字母数量
Task: Write a function count_vowels(words) to count the number of vowels (a, e, i, o, u) in each word.
示例 / Example:
输入 Input: ["apple", "sky", "orange"]
输出 Output: [2, 0, 3]答案 / Answer:
def count_vowels(words):
vowels = "aeiou"
result = []
for w in words:
count = sum(1 for c in w if c.lower() in vowels)
result.append(count)
return result
print(count_vowels(["apple", "sky", "orange"]))第11题：两个列表按位相加
Task: Given two lists of the same length, add corresponding elements.
示例 / Example:
输入 Input: a = [3, 5, 2], b = [7, 1, 4]
输出 Output: [10, 6, 6]答案 / Answer:
a = [3, 5, 2]
b = [7, 1, 4]
result = [a[i] + b[i] for i in range(len(a))]
print(result)第12题：筛选短单词
Task: Print all words whose length is less than 5.
示例 / Example:
输入 Input: ["elephant", "dog", "cat", "bear", "tiger"]
输出 Output:
dog
cat
bear答案 / Answer:
words = ["elephant", "dog", "cat", "bear", "tiger"]
for w in words:
if len(w) < 5:
print(w)第13题：用索引序号替换字母
Task: Convert each word to a string of index numbers joined by hyphens.
示例 / Example:
输入 Input: ["hi", "sun"]
输出 Output: ["0-1", "0-1-2"]答案 / Answer:
def replace_with_index(words):
result = []
for w in words:
indices = "-".join(str(i) for i in range(len(w)))
result.append(indices)
return result
print(replace_with_index(["hi", "sun"]))第14题：计算平均值
Task: Calculate and print the average of numbers in a list.
示例 / Example:
输入 Input: [10, 15, 25]
输出 Output: Average: 16.6666667答案 / Answer:
nums = [10, 15, 25]
average = sum(nums) / len(nums)
print("Average:", average)第15题：判断是否为回文字符串
Task: Write a function to check if a word reads the same forward and backward.
示例 / Example:
输入 Input: "level" → True
输入 Input: "python" → False答案 / Answer:
def is_palindrome(word):
return word == word[::-1]
print(is_palindrome("level"))
print(is_palindrome("python"))第16题：用连字符连接字符串
Task: Join all strings in a list using hyphens.
示例 / Example:
输入 Input: ["red", "green", "blue"]
输出 Output: red-green-blue答案 / Answer:
def combine(words):
return "-".join(words)
print(combine(["red", "green", "blue"]))第17题：打印奇数并求和
Task: Input an integer n. Print all odd numbers from 1 to n and their total sum.
示例 / Example:
输入 Input: 10
输出 Output:
Odd numbers are: 1 3 5 7 9
Sum of odd numbers: 25答案 / Answer:
n = int(input("Enter a number: "))
odd_sum = 0
print("Odd numbers are:", end=" ")
for i in range(1, n + 1):
if i % 2 != 0:
print(i, end=" ")
odd_sum += i
print("\nSum of odd numbers:", odd_sum)第18题：天数换算成几周几天
Task:
编写一个函数，将给定的天数转换为“几周几天”。
示例 / Example:
输入 Input: 10
输出 Output: "1 week(s) and 3 day(s)"答案 / Answer:
def days_to_weeks(days):
weeks = days // 7
remaining_days = days % 7
return f"{weeks} week(s) and {remaining_days} day(s)"
print(days_to_weeks(10))第19题：将列表转换为字典
Task:
将一个列表 [key1, value1, key2, value2, ...] 转换为字典。
示例 / Example:
输入 Input: ["name", "Tom", "age", "18"]
输出 Output: {"name": "Tom", "age": "18"}答案 / Answer:
def list_to_dict(lst):
result = {}
for i in range(0, len(lst), 2):
result[lst[i]] = lst[i + 1]
return result
print(list_to_dict(["name", "Tom", "age", "18"]))第20题：统计字母出现次数
Task:
统计字符串中每个字母出现的次数，返回字典。
示例 / Example:
输入 Input: "banana"
输出 Output: {"b": 1, "a": 3, "n": 2}答案 / Answer:
def count_letters(word):
counts = {}
for ch in word:
counts[ch] = counts.get(ch, 0) + 1
return counts
print(count_letters("banana"))第21题：控制台输入多个单词，返回最短的
Task:
让用户在控制台输入多个单词（用空格分隔），返回最短的单词。
示例 / Example:
输入 Input: (console) hello sun python
输出 Output: sun答案 / Answer:
def shortest_word():
words = input("请输入多个单词（空格分隔）：").split()
shortest = min(words, key=len)
print(shortest)
# 示例运行
# shortest_word()第22题：保留列表中只含 'a' 的单词
Task:
筛选出包含字母 'a' 的单词，只保留这些单词。
示例 / Example:
输入 Input: ["apple", "sun", "banana", "pear"]
输出 Output: ["apple", "banana", "pear"]答案 / Answer:
def keep_words_with_a(words):
return [w for w in words if 'a' in w]
print(keep_words_with_a(["apple", "sun", "banana", "pear"]))Python 基础编程练习（编号 23–55）
涵盖知识点： for/while 循环、条件判断、列表操作、字符串处理、字典、函数定义、
input()、列表推导式、切片、range()、join()、split()、列表↔字典↔字符串互转
23
Task: Print all multiples of 3 from 1 to 30, separated by spaces.
示例 / Example Output:
3 6 9 12 15 18 21 24 27 3024
Task: Calculate the sum of all integers from 1 to 100.
输出 / Output:
505025
Task: Write a function find_max(nums) that returns the largest number in a list (without using max()).
示例 / Example:
输入 Input: [3, 8, 1, 12, 5]
输出 Output: 1226
Task: Write a function find_min(nums) that returns the smallest number in a list.
示例 / Example:
输入 Input: [9, 4, 7, 2, 6]
输出 Output: 227
Task: Count how many positive numbers are in the list.
示例 / Example:
输入 Input: [-3, 5, 0, 8, -1, 2]
输出 Output: 328
Task: Reverse a list without using reverse() or [::-1].
示例 / Example:
输入 Input: [1, 2, 3, 4, 5]
输出 Output: [5, 4, 3, 2, 1]29
Task: Remove duplicate values from a list, preserving order.
示例 / Example:
输入 Input: [1, 2, 2, 3, 4, 4, 5]
输出 Output: [1, 2, 3, 4, 5]30
Task: Write a function is_prime(n) that returns True if n is a prime number.
示例 / Example:
输入 Input: 7 → True
输入 Input: 10 → False31
Task: Calculate the factorial of a given number n (i.e., n!).
示例 / Example:
输入 Input: 5
输出 Output: 12032
Task: Print the first n numbers of the Fibonacci sequence.
示例 / Example:
输入 Input: 8
输出 Output: 0 1 1 2 3 5 8 1333
Task: Count the total number of vowels in a string.
示例 / Example:
输入 Input: "Hello World"
输出 Output: 334
Task: Swap the case of each character in a string.
示例 / Example:
输入 Input: "Hello World"
输出 Output: "hELLO wORLD"35
Task: Check whether a list is sorted in ascending order.
示例 / Example:
输入 Input: [1, 3, 5, 7] → True
输入 Input: [1, 3, 2, 4] → False36
Task: Find the second-largest number in a list.
示例 / Example:
输入 Input: [4, 1, 9, 7, 3]
输出 Output: 737
Task: Capitalize the first letter of each word in a sentence.
示例 / Example:
输入 Input: "hello python world"
输出 Output: "Hello Python World"38
Task: Count how many words are in a sentence.
示例 / Example:
输入 Input: "I love programming in Python"
输出 Output: 539
Task: Compute the greatest common divisor of two integers.
示例 / Example:
输入 Input: 12, 18
输出 Output: 640
Task: Convert Celsius to Fahrenheit using the formula F = C * 9/5 + 32.
示例 / Example:
输入 Input: 25
输出 Output: 77.041
Task: Determine whether a given year is a leap year.
示例 / Example:
输入 Input: 2024 → True
输入 Input: 2023 → False42
Task: Return a new list with each number squared.
示例 / Example:
输入 Input: [1, 2, 3, 4]
输出 Output: [1, 4, 9, 16]43
Task: Merge two dictionaries into one.
示例 / Example:
输入 Input: {"a": 1, "b": 2}, {"c": 3, "d": 4}
输出 Output: {"a": 1, "b": 2, "c": 3, "d": 4}44
Task: Return the key with the maximum value in a dictionary.
示例 / Example:
输入 Input: {"a": 10, "b": 25, "c": 7}
输出 Output: "b"45
Task: Calculate the product of all numbers in a list.
示例 / Example:
输入 Input: [1, 2, 3, 4]
输出 Output: 2446
Task: Check if a string contains any digit.
示例 / Example:
输入 Input: "hello123" → True
输入 Input: "hello" → False47
Task: Remove all whitespace from a given string.
示例 / Example:
输入 Input: " hello world "
输出 Output: "helloworld"48
Task: Return a list of indices where the numbers are even.
示例 / Example:
输入 Input: [1, 2, 3, 4, 5, 6]
输出 Output: [1, 3, 5]49
Task: Convert a number of seconds into HH:MM:SS format.
示例 / Example:
输入 Input: 3661
输出 Output: "01:01:01"50
Task: Return the common elements between two lists.
示例 / Example:
输入 Input: [1, 2, 3, 4], [3, 4, 5, 6]
输出 Output: [3, 4]51
Task: Return a dictionary mapping each word to its length.
示例 / Example:
输入 Input: "I love python"
输出 Output: {"I": 1, "love": 4, "python": 6}52
Task: Print the 9×9 multiplication table.
示例 / Example Output（部分）:
1*1=1
2*1=2 2*2=4
3*1=3 3*2=6 3*3=9
...
9*1=9 9*2=18 ... 9*9=8153
Task: Convert a list of words into a dictionary where each key is a unique word and each value is the number of times that word appears in the list (word frequency count).
示例 / Example:
输入 Input: ["apple", "banana", "apple", "orange", "banana", "apple"]
输出 Output: {"apple": 3, "banana": 2, "orange": 1}进阶 / Bonus: 试试用一个英文句子作为输入，先 split 成 list，再统计每个单词的出现次数。
输入 Input: "the cat and the dog and the bird"
输出 Output: {"the": 3, "cat": 1, "and": 2, "dog": 1, "bird": 1}54
Task: Convert a dictionary into a list of (key, value) tuples (or a list of [key, value] pairs).
示例 / Example:
输入 Input: {"name": "Alice", "age": 20, "city": "Sydney"}
输出 Output: [("name", "Alice"), ("age", 20), ("city", "Sydney")]进阶 / Bonus: 只返回所有 keys 的列表 和 所有 values 的列表。
输入 Input: {"a": 1, "b": 2, "c": 3}
输出 Output:
keys = ["a", "b", "c"]
values = [1, 2, 3]55
Task: Convert a string into a list. Implement the following three conversions:
- Convert a string into a list of characters.
- Convert a sentence into a list of words (split by spaces).
- Convert a comma-separated string into a list of items (strip extra spaces).
示例 / Example:
输入 Input 1: "hello"
输出 Output 1: ["h", "e", "l", "l", "o"]
输入 Input 2: "I love python programming"
输出 Output 2: ["I", "love", "python", "programming"]
输入 Input 3: "apple, banana, orange, grape"
输出 Output 3: ["apple", "banana", "orange", "grape"]56
Write a function called count_words that takes a list of words as a parameter and returns a dictionary where each unique word is a key and its value is the number of times that word appears in the list.
Function signature:
def count_words(words: list) -> dict:Requirements:
- The function should be case-sensitive (e.g., “Hello” and “hello” are different words)
- If the input list is empty, return an empty dictionary
- The order of keys in the dictionary does not matter
Example:
words = ["apple", "banana", "apple", "cherry", "banana", "apple"]
result = count_words(words)
print(result)
# Output: {'apple': 3, 'banana': 2, 'cherry': 1}
words = ["hello", "world", "hello"]
result = count_words(words)
print(result)
# Output: {'hello': 2, 'world': 1}
words = []
result = count_words(words)
print(result)
# Output: {}57
Write a function called dict_to_list that takes a dictionary as a parameter and returns a list of tuples. Each tuple should contain a key-value pair from the dictionary, with the key as the first element and the value as the second element.
Function signature:
def dict_to_list(data: dict) -> list:Requirements:
- Each tuple in the list should be in the format (key, value)
- If the input dictionary is empty, return an empty list
- The order of tuples in the list does not matter
Example:
data = {"name": "Alice", "age": 25, "city": "Boston"}
result = dict_to_list(data)
print(result)
# Output: [('name', 'Alice'), ('age', 25), ('city', 'Boston')]
# Note: Order may vary
data = {"apple": 3, "banana": 2}
result = dict_to_list(data)
print(result)
# Output: [('apple', 3), ('banana', 2)]
data = {}
result = dict_to_list(data)
print(result)
# Output: []58
Write a function called calculate_grade_stats that takes a list of student names and a list of their corresponding scores. The function should return a dictionary where each student name is a key and the value is another dictionary containing their score and grade letter.
Function signature:
def calculate_grade_stats(names: list, scores: list) -> dict:Requirements:
- The two lists will always have the same length
- Grade letters are assigned as follows:
- 90-100: “A”
- 80-89: “B”
- 70-79: “C”
- 60-69: “D”
- Below 60: “F”
- Each student’s value should be a dictionary with keys “score” and “grade”
- If both input lists are empty, return an empty dictionary
Example:
names = ["Alice", "Bob", "Charlie"]
scores = [95, 82, 67]
result = calculate_grade_stats(names, scores)
print(result)
# Output: {
# 'Alice': {'score': 95, 'grade': 'A'},
# 'Bob': {'score': 82, 'grade': 'B'},
# 'Charlie': {'score': 67, 'grade': 'D'}
# }
names = ["David", "Emma"]
scores = [78, 55]
result = calculate_grade_stats(names, scores)
print(result)
# Output: {
# 'David': {'score': 78, 'grade': 'C'},
# 'Emma': {'score': 55, 'grade': 'F'}
# }
names = []
scores = []
result = calculate_grade_stats(names, scores)
print(result)
# Output: {}最后更新 · 2026-05-19 23:52