1. python输出

# \转义字符
print('I\'am developer') # 输出\
print(r'I\'am developer') # r''里面的内容不允许转义

# ord()函数获取字符的整数表示,chr()函数把编码转换为对应的字符
ord('A') # 输出 65
ord('') # 输出 20013
chr(66) # 输出B
chr(25991) # 输出文
# 如果知道字符的整数编码,还可以用十六进制这么写str:
print('\u4e2d\u6587') # 输出中文
# %d 整数 %f 浮点数 %s 字符串 %x十六进制整数
print('%2d-%02d' % (3, 1)) #输出 3-01 3的前面会有一个空格 
print('%.2f' % 3.1415926) #输出3.14
# 乘法口诀
a = 1
while a < 10:
    b = 1
    while b <= a:
        print ("%d*%d = %02d "%(b , a ,a*b),end="")
        b+=1
    print("\r")
    a+=1

#    1*1 = 01
#    1*2 = 02 2*2 = 04
#    1*3 = 03 2*3 = 06 3*3 = 09
#    1*4 = 04 2*4 = 08 3*4 = 12 4*4 = 16
#    1*5 = 05 2*5 = 10 3*5 = 15 4*5 = 20 5*5 = 25
#    1*6 = 06 2*6 = 12 3*6 = 18 4*6 = 24 5*6 = 30 6*6 = 36
#    1*7 = 07 2*7 = 14 3*7 = 21 4*7 = 28 5*7 = 35 6*7 = 42 7*7 = 49
#    1*8 = 08 2*8 = 16 3*8 = 24 4*8 = 32 5*8 = 40 6*8 = 48 7*8 = 56 8*8 = 64
#    1*9 = 09 2*9 = 18 3*9 = 27 4*9 = 36 5*9 = 45 6*9 = 54 7*9 = 63 8*9 = 72 9*9 = 81