运算符
算数运算
如a=10,b=20
+两个数相加 a+b=30
-两个数相减 a-b=-10
*两个数相乘 a*****b =200
/两个数相除b/a=2
%取模，并返回余数b%a=0
幂，a**b=10的20次方
.strip()去除多余空格字符串
.isdigit()判断是否为数字字符串
time库
-
获取时间
time.timr()
time.ctime()
time.gmtime()
格式化
time.strftime
time.strptime
-
程序计时
time.sleep()
time.perf_counter()
利用time库写一个进度条
-
源代码
import time count = 10
print("....请开始执行....")
for i in range(count + 1):
a = "#" * i
b = "." * (count - i)
c = (i/count) * 100
print(f"[{a}->{b}]{c}%")
time.sleep(0.2)
print("......执行结束.....")
优化后的进度条
-
源代码
import time print("开始执行".center(50, '-'))#把开始执行放中间，用50个-包围
start = time.perf_counter()
count = 100
for i in range(count + 1):
a = "#" * i
b = "." * (count - i)
c = (i/count) * 100
res = time.perf_counter() - start
#print(f"\r[{a}->{b}]{c:.2f}%{res:.2f}s",end="")
print(f"\033[1;31m\r[{a}->{b}]{c:.2f}%{res:.2f}s\033[0m", end="")
# 上面加了就可以改变颜色
#print(f"\033[1;31;40m\r[{a}->{b}]{c:.2f}%{res:.2f}s\033[0m", end="")
#上面这行还可以改变进度条背景颜色
time.sleep(0.05)
print("\n" + "结束执行".center(50, '-')) ```