两数之和
number1 = 1.5
number2 = 3.8
sum = number1 + number2
print(f"{number1} + {number2} = {sum}")
数字的阶乘
def get_factorial(number):
result = 1
while number > 0:
result = result * number
number = number - 1
return result
print("factorial 6 = ",get_factorial(6))
print("factorial 3 = ",get_factorial(3))
print("factorial 100 = ",get_factorial(100))
计算圆的面积
import math
def compute_area_of_circle(r):
return round(math.pi * r * r, 2)
print("area of 2 is:", compute_area_of_circle(2))
print("area of 3.14 is:", compute_area_of_circle(3.14))
print("area of 6.78 is:", compute_area_of_circle(6.18))
区间内所有的素数
def is_prime(number):
if number in (1, 2):
return True
for idx in range(2, number):
if number % idx == 0:
return False
return True
def print_primes(begin, end):
for number in range(begin, end + 1):
if is_prime(number):
print(f"{number} is a prime")
begin = 11
end = 25
print_primes(begin, end)
求前N个数字的平方和
def sum_of_square(n):
result = 0
for number in range(1, n + 1):
result += number * number
return result
print("sum of squre 3:", sum_of_square(3))
print("sum of squre 5:", sum_of_square(5))
print("sum of squre 10:", sum_of_square(10))
Python计算列表数字的和
def sum_of_list(param_list):
total = 0
for item in param_list:
total += item
return total
list1 = [1, 2, 3, 4]
list2 = [17, 5, 3, 5]
print(f"sum of {list1},", sum_of_list(list1))
print(f"sum of {list2},", sum_of_list(list2))
数字范围内的所有偶数
def get_even_numbers(begin, end):
result = []
for item in range (begin, end):
if item % 2 == 0:
result.append(item)
return result
begin = 4
end = 15
print(f"begin={begin}, end={end}, even numbers: ", get_even_numbers(begin, end))
# data = [item for item in range(begin, end) if item % 2 == 0]
# print(f"begin={begin}, end={end}, even numbers: ", data)
从列表中移除多个元素
def remove_elements_from_list(lista, listb):
for item in listb:
lista.remove(item)
return lista
lista = [3, 5, 7, 9, 11, 13]
listb = [7, 11]
print(f"from {lista} remove {listb} result : ", remove_elements_from_list(lista, listb))
# data = [item for item in lista if item not in listb]
# print(f"from {lista} remove {listb} result : ", data)
怎样实现对列表的去重
def get_unique_list(lista):
result = []
for item in lista:
if item not in result:
result.append(item)
return result
lista = [10, 20, 30, 10, 20]
print(f"source list {lista}, unique list:", get_unique_list(lista))
# print(f"source list {lista}, unique list:", list(set(lista)))
实现对简单列表进行排序
lista = [20, 40, 30, 50, 10]
# lista.sort()
listb = sorted(lista, reverse=True) # reverse函数反序排列
print(f"lista is {lista}")
print(f"listb is {listb}")
实现学生成绩的排序
students = [
{"sno": 101, "sname": "小张", "sgrade": 88},
{"sno": 102, "sname": "小王", "sgrade": 99},
{"sno": 103, "sname": "小李", "sgrade": 66},
{"sno": 104, "sname": "小赵", "sgrade": 77},
]
students_sort = sorted(students, key=lambda x: x["sgrade"], reverse=True)
print(f"source {students}, sort result: {students_sort}")
读取成绩文件实现排序
def read_file():
result = []
with open("./student_grade_input.txt") as fin:
for line in fin:
line = line[:-1]
result.append(line.split(","))
return result
def sort_grades(datas):
return sorted(datas,
key=lambda x: int(x[2]),
reverse=True)
def write_file(datas):
with open("./student_grade_input.txt", "w") as fout:
for data in datas:
fout.write(",".join(data) + "\n")
# 读取文件
datas = read_file()
print("read_file datas:", datas)
# 排序数据
datas = sort_grades(datas)
print("sort_grades datas:", datas)
# 写出文件
write_file(datas)
读取成绩文件计算最高分最低分平均分
def compute_score():
scores = []
with open("./student_garde_input.txt") as fin:
for line in fin:
line = line[:-1]
fields = line.sqlit(",")
scores.append(int(fields[-1]))
max_score = max(scores)
min_score = min(scores)
avg_score = round(sum(scores) / len(scores), 2)
return max_score,min_score,avg_score
max_score, min_score, avg_score = compute_score()
print(f"max_score={max_score}, min_score={max_score}, avg_score{avg_score}")
统计英语文章出现最多的单词数目
word_count = {}
with open("./Beginner Guide to Python.txt") as fin:
for line in fin:
line = line[:-1]
words = line.split()
for word in words:
if word not in word_count:
word_count[word] = 0
word_count[word] += 1
print(
sorted(
word_count.items(),
key=lambda x: x[1],
reverse=True
)[:10]
)
统计目录下的文件大小
import os
print(os.path.getsize("Beginner Guide to Python.txt"))
sum_size = 0
for file in os.listdir("."):
if os.path.isfile(file):
sum_size += os.path.getsize(file)
print("all size of dir:", sum_size/1000)
按文件后缀整理文件夹
import os
import shutil
dir = "./arrange_dir"
for file in os.listdir(dir):
ext = os.path.splitext(file)[1]
ext = ext[1:]
if not os.path.isdir(f"{dir}/{ext}"):
os.mkdir(f"{dir}/{ext}")
source_path = f"{dir}/{ext}/{file}"
target_path = f"{dir}/{ext}/{file}"
shutil.move(source_path, target_path)
计算每个班级的最高分最低分平均分
# key: course，value: grade list
course_grades = {}
with open("course_student_grade_input.txt",encoding='utf-8') as fin:
for line in fin:
line = line[:-1]
course, sno, sname, grade = line.split(",")
if course not in course_grades:
course_grades[course] = []
course_grades[course].append(int(grade))
print(course_grades)
for course, grades in course_grades.items():
print(
course,
max(grades),
min(grades),
sum(grades) / len(grades)
)
实现不同文件的关联
course_teacher_map = {}
with open("./datas/course_teacher.txt") as fin:
for line in fin:
line = line[:-1]
course, teacher = line.split(",")
course_teacher_map[course] = teacher
print(course_teacher_map)
with open("./course_student_grade_input.txt") as fin:
for line in fin:
line = line[:-1]
course, sno, sname, sgrade = line.split(",")
teacher = course_teacher_map.get(course)
print(course, teacher, sno, sname, sgrade)
实现批量Txt文件的合并
小知识: Python读取文件的两个方法 方法1:按行读取 for line in fin 方法2: 一次读取所有内容到一个字符串 content = fin.read()
import os
data_dir = "./datas/many_texts"
contents = []
for file in os.listdir(data_dir):
file_path = f"{data_dir}/{file}"
if os.path.isfile(file_path) and file.endswith(".txt"):
with open(file_path) as fin:
contents.append(fin.read())
final_contentl= "\n".join(contents)
with open("./datas/many_texts.txt" "w") as fout:
fout.write(final_content)
统计每个兴趣的学生人数
like_count = {}
with open("./datas/student_like.txt") as fin:
for line in fin:
line = line[:-1]
sname, likes = line.split("")
like_list = likes.split(",")
for like in like_list:
if like not in like_count:
like_count[like] = 0
like_count[like] += 1
print(like_count)
获取当前的日期和时间
import datetime
curr_datetime = datetime.datetime.now()
print(curr_datetime, type(curr_datetime))
# date time to string
str_time = curr_datetime.strftime("%Y-%m-d %H:%M:%S")
print("str_time", str_time)
print("year", curr_datetime.year)
print("month", curr_datetime.month)
print("day", curr_datetime.day)
print("hour", curr_datetime.hour)
print("minute", curr_datetime.minute)
print("second", curr_datetime.second)
计算两个日期相隔的天数
import datetime
birthday = "1999-9-9"
birthday_date = datetime.datetime.strptime(birthday, "%Y-%m-%d")
print(birthday_date, type(birthday_date))
curr_datetime = datetime.datetime.now()
print(curr_datetime, type(curr_datetime))
minus_datetime = curr_datetime - birthday_date
print(minus_datetime, type(minus_datetime))
print(minus_datetime.days)
print(minus_datetime.days / 365)
计算任意日期7天前的日期
import datetime
def get_diff_days(pdate, days):
pdate_obj = datetime.datetime.strptime(pdate, '%Y-%m-%d')
time_gap = datetime.timedelta(days=days)
pdate_result = pdate_obj - time_gap
return pdate_result.strftime("%Y-%m-%d")
print(get_diff_days("2023-04-28",1))
print(get_diff_days("2023-04-28",3))
print(get_diff_days("2023-04-28",7))
print(get_diff_days("2023-04-01",3))
计算日期范围的所有日期
import datetime
def get_date_range(begin_date, end_date):
date_list = []
while begin_date <= end_date:
date_list.append(begin_date)
begin_date_object = datetime.datetime.strptime(begin_date, "%Y-%m-%d")
days1_timedelta = datetime.timedelta(days=1)
begin_date = (begin_date_object + days1_timedelta).strftime("%Y-%m-%d")
return date_list
begin_date = "2023-04-28"
end_date = "2023-05-03"
date_list = get_date_range(begin_date, end_date)
print(date_list)
将Unix时间戳转换成格式化日期
import datetime
unix_time = 1691847647
datetime_obj = datetime.datetime.fromtimestamp(unix_time)
datetime_str = datetime_obj.strftime("%Y-%m-%d %H:%M:%S")
print(datetime_str)
计算日期数据周同比
import datetime
date_sale = {}
is_first_line = True
with open("./datas/date_sale_data.txt") as fin:
for line in fin:
if is_first_line:
is_first_line = False
continue
line = line[:-1]
date, sale_number = line.split("\t")
date_sale[date] = float(sale_number)
def get_diff_days(date, days):
curr_date = datetime.datetime.strptime(date, "Y-%m-%d")
timedelta = datetime.timedelta(days=-days)
return (curr_date + timedelta).strftime("%Y-%m-%d")
for date, sale_number in date_sale.items():
date7 = get_diff_days(date, 7)
sale_number7 = date_sale.get(date7, 0)
if sale_number7 == 0:
print(date, sale_number, 0)
else:
week_diff = (sale_number - sale_number7) / sale_number7
print(date, sale_number, date7, sale_number7, week_diff)
正则表达式判断字符串是否是日期
import re
def date_is_right(date):
return re.match("\d{4}-\d{2}-\d{2}", date) is not None
date1= "2023-05-20"
date2= "202-05-20"
date3= "2023/05-20"
date4 = "20210520"
date5 = "20a10520"
print(date1, date_is_right(date1))
print(date2, date_is_right(date2))
print(date3, date_is_right(date3))
print(date4, date_is_right(date4))
print(date5, date_is_right(date5))
自动提取电子邮箱地址
content = """
寻隐者12345@qq.com不遇
朝代:唐asdf12dsa#abc.com代
作python666@163.cn者: 贾岛
松下问童子，言师python-abc@163com采药去。
只在python_ant-666@sina.net此山中，云深不知处。
"""
# python666@163.cn
import re
pattern = re.compile(r"""
[a-zA-Z0-9_-]+
@
[a-zA-Z0-9]+
\.
[a-zA-z]{2,4}
""",re.VERBOSE)
results = pattern.findall(content)
for result in results:
print(result)
验证用户密码是否规范
"""
1.长度位于[6, 20]之间
2.必须包含至少1个小写字母
3.必须包含至少1个大写字母
4.必须包含至少1个数字
5.必须包含至少1个特殊字符
返回
True, None
或者 False, 原因
"""
import re
def check_password(password):
if not 6 <= len(password) <= 20:
return False, "密码必须在6~20之间"
if not re.findall(r"[a-z]", password):
return False, "必须包含至少1个小写字母"
if not re.findall(r"[A-Z]", password):
return False, "必须包含至少1个大写字母"
if not re.findall(r"[0-9]", password):
return False, "必须包含至少1个数字"
if not re.findall(r"[^0-9a-zA-Z]", password):
return False, "必须包含至少1个特殊字符"
return True, None
print("Helloworld#666", check_password("Helloworld#666"))
print("Helloworld#",check_password("Helloworld#"))
print("helloworld#666", check_password("helloworld#666"))
print("Helloworld666", check_password("Helloworld666"))
提取商品价格
content = """
小明上街买菜
买了1斤黄瓜花了8元;
买了2斤葡萄花了13.5元;
买了3斤白菜花了5.4元;
"""
# 要求提取 (1、黄瓜、8)、 (2、葡萄、13.5) 、 (3、白菜、5.4)
import re
for line in content.split("\n"):
pattern = r"(\d)斤(.*)花了(\d+(\.\d+)?)元"
match = re.search(pattern, line)
if match:
print(f"{match.group(1)}\t{match.group(2)}\t{match.group(3)}")
给文章中手机号打马赛克效果
content = """
白日依19989881888山尽，黄河入45645546468798978海流。
欲穷12345千里目，更上15619292345一层楼。
"""
import re
pattern = r"(1[3-9])\d{9}"
print(re.sub(pattern, r"\1#####", content))
进行多种日期格式的标准化
# 目标:2023-05-28
content = """
白日依2023/05/26山尽,黄河入2023.05.27海流。
欲穷05-28-2023千里目,更上5/29/2023一层楼。
欲穷04-28-2023千里目,更上4/29/2023一层楼。
"""
import re
content = re.sub(r"(\d{4})/(\d{2})/(\d{2})", r"\1-\2-\3", content)
print(content)
content = re.sub(r"(\d{4})\.(\d{2})\.(\d{2})", r"\1-\2-\3", content)
print(content)
content = re.sub(r"(\d{2})-(\d{2})-(\d{4})", r"\3-\1-\2", content)
print(content)
content = re.sub(r"(\d{1})/(\d{2})/(\d{4})", r"\3-0\1-\2", content)
print(content)
实现英文分词计算词频
import re
with open("./Beginner Guide to Python.txt") as fin:
content = fin.read()
# print(content.split())
words = re.split(r"[\s.()-?]+", content)
import pandas as pd
print(pd.Series(words).value_counts()[:20])
实现中文文章分词
content = """
春姑娘悄悄地来到了我们的校园!
绿油油的小草争着抢着从地下探出头来，东张西望地看着四周。
池塘边的柳树，抽出了新的柳枝和柳叶，微风轻轻一吹，柳树就晃动着自己的秀发。
花园里各种各样的花儿都开了，
有艳红的玫瑰花、粉色的桃花、雪白的梨花......五颜六色，美不胜收。
"""
import jieba
import re
content = re.sub(r"[\s。…，、]","", content)
word_list = jieba.cut(content)
print(list(word_list))
统计《鹿鼎记》小说中的人名
# content = “李明喜欢韩梅梅，他俩早恋了"
with open("./datas/鹿鼎记.txt") as fin:
content = fin.read()
import jieba.posseg as posseg
words = []
for word, flag in posseg.cut(content):
if flag == "nr":
words.append(word)
import pandas as pd
print(pd.Series(words).value_counts()[:20])
数组插入一个数组
if __name__ == '__main__':
# 方法一 ： 0 作为加入数字的占位符
a = [1,4,6,9,13,16,19,28,40,100,0]
print ('原始列表:')
for i in range(len(a)):
print (a[i])
number = int(input("\n插入一个数字:\n"))
end = a[9]
if number > end:
a[10] = number
else:
for i in range(10):
if a[i] > number:
temp1 = a[i]
a[i] = number
for j in range(i + 1,11):
temp2 = a[j]
a[j] = temp1
temp1 = temp2
break
print ('排序后列表:')
for i in range(11):
print (a[i])
将一个数组逆序输出
a = [1, 2, 3,4,5]
for i in range(0,(len(a)-1)//2):
temp= a[i]
a[i] = a[len(a)-i-1]
a[len(a)-i-1] = temp
print(a)
模仿静态变量的用法
class Test :
var = 0
def test(self):
self.var += 1
print(self.var)
a = Test()
print(Test.var)
print(a.var)
a.test()
a.test()
a.test()
print(a.var)
print(Test.var)
学习使用atuo定义变量的用法
num = 2
def test():
num = 1
print("test num: %d" % num)
num += 1
for i in range(3):
print("num: %d" % num)
num += 1
test()
模仿静态变量(static)另一案例
class Test:
num = 1
def test(self):
self.num += 1
print(self.num)
num = 1
a = Test()
print(Test.num) # 1
num += 1
print(num) # 2
print(a.num) # 1
a.test()
print(a.num) # 2
print(num) # 2
print(Test.num) # 1
两个矩阵相加
x = [[12,7,3],
[4,5,6],
[7,8,9]]
y = [[5,8,1],
[6,7,3],
[4,5,9]]
z = [[0,0,0],
[0,0,0],
[0,0,0]]
for i in range(3):
for j in range(3):
z[i][j] = x[i][j] + y[i][j]
for i in z:
print(i)
统计1到100之和
sum = 0
for i in range(1,101):
sum += i
print(sum)
两个变量值互换
a = 10
b = 20
# 第三方变量
# c = a
# a = b
# b = c
# print(a,b)
# 加减法
# a = a+b
# b = a-b
# a = a-b
# print(a,b)
# 语言特性
a,b = b,a
print(a)
print(b)
数字比较
i = 10
j = 20
if i > j:
print(">")
elif i == j:
print("==")
elif i < j:
print("<")
else:
print("未知")
使用lambda来创建匿名函数
POWER = lambda x,y : x ** y
a = 10
b = 20
print(POWER(10,20))
输出一个随机数
import random
print(random.randint(10,20))
print(random.random())
print(random.uniform(10,20))
学习使用按位与 &
if __name__ == '__name__':
a = 0x77
b = a & 3
print ('a & b = %d' % b)
b &= 7
print ('a & b = %d' %b)
学习使用按位或 _
#!/usr/bin/python
# -*- coding: UTF-8 -*-
if __name__ == '__main__':
a = 0o77
b = a | 3
print ('a | b is %d' % b)
b |= 7
print ('a | b is %d' % b)
学习使用按位异 ^
#!/usr/bin/python
# -*- coding: UTF-8 -*-
if __name__ == '__main__':
a = 0o77
b = a ^ 3
print ('The a ^ 3 = %d' % b)
b ^= 7
print ('The a ^ b = %d' % b)
取一个整数a从右端开始的4~7位
#!/usr/bin/python
# -*- coding: UTF-8 -*-
if __name__ == '__main__':
a = int(input('input a number:\n'))
b = a >> 4
c = ~(~0 << 4)
d = b & c
print ('%o\t%o' %(a,d))
学习使用按位取反 ~
#!/usr/bin/python
# -*- coding: UTF-8 -*-
a = 7
b = ~a
c = -7
d = ~c
print ('变量 a 取反结果为： %d' % b)
print ('变量 c 取反结果为： %d' % d)
统计字符串长度
str = input("Please input the string:")
print("The length of your string is %d" % len(str))
打印出杨辉三角形
a = []
n = int(input("n:"))
for i in range(n):
a.append([])
for j in range(i+1):
if j==0 or j==i:
a[i].append(1)
else:
a[i].append(a[i-1][j]+a[i-1][j-1])
for i in a: print(i)
查找字符串
str1 = input()
str2 = input()
print(str1.find(str2))
输入三个数按大小顺序输出
num1 = int(input())
num2 = int(input())
num3 = int(input())
# a = []
# a.append(num1)
# a.append(num2)
# a.append(num3)
# a.sort( )
# print(a)
if num1 > num2:
if num2 > num3:
print(num1,num2,num3)
else:
print(num1,num3,num1)
else: # num1 <= num2
if num2 < num3:
print(num3,num2,num1)
else: # num3 <= num2
if num1 > num3:
print(num2,num1,num3)
else:
print(num2,num3,num1)
输入数组，最大的与第一个元素交换，最小的与最后一个元素交换，输出数组
def inp(numbers):
for i in range(6):
numbers.append(int(raw_input('输入一个数字:\n')))
p = 0
def arr_max(array):
max = 0
for i in range(1,len(array) - 1):
p = i
if array[p] > array[max] : max = p
k = max
array[0],array[k] = array[k],array[0]
def arr_min(array):
min = 0
for i in range(1,len(array) - 1):
p = i
if array[p] < array[min] : min = p
l = min
array[5],array[l] = array[l],array[5]
def outp(numbers):
for i in range(len(numbers)):
print numbers[i]
if __name__ == '__main__':
array = []
inp(array) # 输入 6 个数字并放入数组
arr_max(array) # 获取最大元素并与第一个元素交换
arr_min(array) # 获取最小元素并与最后一个元素交换
print '计算结果：'
outp(array)
有n个整数，使其前面各数顺序向后移m个位位置，最后m个数变成最前面的
a = [2,8,6,1,78,45,34,2]
b = [0,0,0,0, 0, 0, 0,0]
m = int(input("m:"))
t = 0
for i in range(m,len(b)):
b[i] = a[t]
t += 1
for i in range(len(b) - t):
b[i] = a[t]
t += 1
print(b)
有n个人围成一圈，顺序排号，从第一个人开始报数 (从1到3报数)
if __name__ == '__main__':
nmax = 50
n = int(raw_input('请输入总人数:'))
num = []
for i in range(n):
num.append(i + 1)
i = 0
k = 0
m = 0
while m < n - 1:
if num[i] != 0 : k += 1
if k == 3:
num[i] = 0
k = 0
m += 1
i += 1
if i == n : i = 0
i = 0
while num[i] == 0: i += 1
print num[i]
写一个函数，求一个字符串的长度，在main函数中输入字符串，并输出其长度
def my_len(s):
i = 0
for each in s:
i += 1
return i
s = input("Please input the string here:")
print(my_len(s))
编写input()和output()函数输入，输出5个学生的数据记录
n = int(input("n:"))
student = []
def input_stu():
for i in range(n):
print("------第%d位学生的信息录入开始------" % (i+1))
name = input("请输入学生姓名: ")
chinese = int(input("请输入%s的语文成绩: " % name))
math = int(input("请输入%s的数学成绩: " % name))
english = int(input("请输入%s的英语成绩: " % name))
student.append([])
student[i].append(name)
student[i].append(chinese)
student[i].append(math)
student[i].append(english)
# 打印学生信息
def output_stu():
for i in student:
print("-------%s-------" % i[0])
print("chinese: %d" % i[1])
print("math: %d" % i[2])
print("english: %d" % i[3])
input_stu()
output_stu()
创建一个链表格
ptr = [input("please input the number:") for x in range(5)]
print(ptr)
反向输出一个链表
ptr = [input("please input the number:") for x in range(5)]
# 1
# ptr.reverse()
# print(ptr)
# 2
for i in range(4,-1,-1):
print(ptr[i])
列表排序及连接
a = [3, 4, 5, 1, 2]
# a.sort(reverse=True)
# print(a)
print(str(123)+'123')
放松一下，算一道简单的题目
if __name__ == '__main__':
for i in range(5):
n = 0
if i != 1: n += 1
if i == 3: n += 1
if i == 4: n += 1
if i != 4: n += 1
if n == 3: print(64 + i)
print(n)
编写一个函数，输入n为偶数时，调用函数求1_2+1_4+...+1
def a(n):
if n%2 == 0:
print(b(n))
else:
print(c(n))
return
def b(n):
# 2 - n
sum = 0
for i in range(2,n+1,2):
sum += 1/i
return sum
def c(n):
# 1 --- n
sum = 0
for i in range(1,n+1,2):
print(i)
return sum
if __name__ == '__main__':
n = int(input("n:"))
a(n)
循环输出列表
a = [s for s in "Fuck you!"]
for i in range(len(a)):
print(a[i],end='')
找到年龄最大的人，并输出。请找出程序中有什么问题
person = {"li":18, "wang": 50, "zhang":20, "sun":22}
m ='li'
for i in person.keys():
if person[m] < person[i]:
m=i
print("%s %d" % (m,person[m]))
字符串排序
str1 = input("string1:")
str2 = input("string2:")
str3 = input("string3:")
print(str1,str2,str3)
if str1>str2: str1,str2 = str2,str1
if str1>str3: str1,str3 = str3,str1
if str2>str3: str2,str3 = str3,str2
print(str1,str2,str3)
猴子分桃
i=1
while 1:
# 0 - 4
temp = i
for j in range(5):
if temp % 5 != 1:
break
else:
temp = (temp-1)/5*4
if j==4:
print(i)
exit()
i += 1
具体如下
题目:809*??=800*??+9*?? 其中??代表的两位数,809*??为四位数，8*??的结果为两位数，9*??的结果为3位数。求??代表的两位数，及809*??后的结果
for i in range(10,100):
a = 809 * i
b = 800 * i
c = 9 * i
if a >= 1000 and a <= 9999 and b>=10 and b<=99 and c>=100 and c<=999 and a==b*100+c:
print(i, a)
八进制转换为十进制
a = "12345"
sum = 0
for i in range(len(a)):
num = ord(a[i]) - ord('0')
(len(a) - i - 1)
sum += num * 8 ** (len(a) - i - 1)
print(sum)
求0-7所能组成的奇数个数
j=4
sum = 0
for i in range(1,11):
if i==2:
j *= 7
elif i>2:
j *= 8
sum += j
print("{0}位数有{1}个".format(i,j))
print("总共有{0}个".format(sum))
连接字符串
# str1 = input()
# str2 = input()
# print(str1+str2)
fenge ="-"
# mylist = ["Ben","Tony","Jacky","Becky","Jason","John"]
mystr = "ABCDEFG"
mystr = fenge.join(mystr)
print(mystr)
输入一个奇数，然后判断最少几个9除于该数的结果为整数
a = int(input("n:"))
b = 9
# 9 / 13
while b%a!=0:
b = b * 10 + 9 # 99
print(len(str(b)))
两个字符串连接程序
a = input()
b = input()
print(a+b)
回答结果 (结构体变量传递)
class student:
x = 0
c = 0
def f(stu):
stu.x = 20
stu.c = 'c'
a = student()
a.X = 3
a.c = 'a'
f(a)
print(a.x,a.c)
读取七个数(1-50)的整数值，每读取一个值，程序打印出该值个数的*
for i in range(7):
num = int(input("num:"))
while not(num>=1 and num<=50):
num = int(input("num:"))
print(num * '*')
某个公司采用公用电话传递数据...
num = int(input("num:"))
a = num % 10
b = num // 10 % 10
c = num // 100 % 10
d = num // 1000
res = 0
res += (a + 5)%10
res *= 10
res += (b + 5)%10
res *= 10
res += (c + 5)%10
res *= 10
res += (d + 5)%10
print(res)
列表使用实例
matrix =[[1, 2, 3],
[4, 5, 6],
[7, 8, 9]]
col2 = [row[0] for row in matrix] # get a column from a matrix
print(col2)
时间函数举例1
if __name__ == '__main__':
import time
print(time.ctime(time.time()))
print(time.asctime(time.localtime(time.time())))
print(time.asctime(time.gmtime(time.time())))
时间函数举例2
import time
start = time.time()
for i in range(1000):
print(i)
end = time.time()
print(end-start)
时间函数举例3,一个猜数游戏，判断一个人反应快慢
import time
import random
ans = random.randint(1,100)
guess = 0
start = time.time()
while guess != ans:
guess = int(input("guess:"))
if guess > ans:
print("大了!")
elif guess < ans:
print("小了!")
else:
print("答对了! 你真帅!")
end = time.time()
print("你猜对答案用了 %d s " % (end-start))
game_time = end-start
if game_time <= 10:
print("你真他娘的是个天才!")
elif game_time <= 20:
print("还不错，你的脑子一般般")
else:
print("你可以去死了，不配玩这个游戏")
从键盘输入一些字符，逐个把它们写到磁盘文件上，指导输入一个#为止
filename = input("请输入文件名: ")
fp = open(filename, "w")
s = input("请输入字符串: ")
while s!='#':
fp.write(s+'\n')
s = input("请输入字符串:")
print("end")
从键盘输入一个字符串，将小写字幕全部转换成大写字母，全部保存
filename = input("filename:")
a = input("str:")
a = a.upper()
fp = open(filename, "w")
fp.write(a)
print("写入完毕!")
fp = open(filename, "r")
print(fp.read())
有两个磁盘文件A和B,各存放一行字母,要求把这两个文件中的信息合并(按字母顺序排列), 输出到一个新文件C中
fp1 = open("test1.txt", "r")
a = fp1.read()
fp1.close()
fp2 = open("test2.txt", "r")
b = fp2.read()
fp2.close()
fp3 = open("test3.txt", "w")
c = list(a+b)
c.sort()
s = ''
s = s.join(c)
fp3.write(s)
fp3.close()
列表转换为字典
keys = ['a','b']
values = [1,2]
print(dict(zip(keys,values)))