Python print函数用法，print 格式化输出

浅浅的花香味﹌ 2022-09-28 16:17 307阅读 0赞

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使用print输出各型的

字符串  
整数  
浮点数  
出度及精度控制  
strHello = ‘Hello Python’  
print strHello

#输出结果：Hello Python
    #直接出字符串

1.格式化输出整数  
python print也支持参数格式化，与C言的printf似，

strHello = “the length of (%s) is %d” %(‘Hello World’,len(‘Hello World’))  
print strHello

#输出果：the length of (Hello World) is 11

2.格式化输出16制整数  
nHex = 0x20

#%x --- hex 十六进制
    #%d --- dec 十进制
    #%d --- oct 八进制

print “nHex = %x,nDec = %d,nOct = %o” %(nHex,nHex,nHex)

#输出结果：nHex = 20,nDec = 32,nOct = 40
    #使用整数的各个制打印同一个数

3.格式化输出浮点数(float)

import math
    #default
    print "PI = %f" % math.pi
    #width = 10,precise = 3,align = left
    print "PI = %10.3f" % math.pi
    #width = 10,precise = 3,align = rigth
    print "PI = %-10.3f" % math.pi
    #前面填充字符
    print "PI = %06d" % int(math.pi)

#输出结果
    #PI = 3.141593
    #PI =      3.142
    #PI = 3.142
    #PI = 000003
    #浮点数的格式化，精度、度和

4.格式化输出字符串(string)
    #precise = 3
    print "%.3s " % ("jcodeer")
    #precise = 4
    print "%.*s" % (4,"jcodeer")
    #width = 10,precise = 3
    print "%10.3s" % ("jcodeer")
    #输出结果：
    #jco
    #jcod
    #       jco
    #同于字符串也存在精度、度和。
    5.输出列表(list)
    l = [1,2,3,4,'jcodeer']
    print l
    #输出结果：[1, 2, 3, 4, 'jcodeer']
    #于list直接打印即可
    '''6.出字典(dictionary)'''
    d = {1:'A',2:'B',3:'C',4:'D'}
    print d
    #输出结果：{1: 'A', 2: 'B', 3: 'C', 4: 'D'}
    #同python也是支持dictionary出的

6.python print自动换行  
print 会自动在行末加上回车,如果不需回车，只需在print语句的结尾添加一个逗号”,“，就可以改变它的行为。

for i in range(0,5):  
print i,  
或直接使用下面的函数进行输出：

sys.stdout.write(“输出的字串”)  
7. 万能的 %r  
将后面给的参数原样打印出来，带有类型信息。

python print %r 案例

formatter = “%r %r %r %r”

print formatter % (1, 2, 3, 4)  
print formatter % (“one”, “two”, “three”, “four”)  
print formatter % (True, False, False, True)  
print formatter % (formatter, formatter, formatter, formatter)  
print formatter % (  
“I had this thing.”,  
“That you could type up right.”,  
“But it didn’t sing.”,  
“So I said goodnight.”  
)  
输出结果：

python [ex8.py][]  
1 2 3 4  
‘one’ ‘two’ ‘three’ ‘four’  
True False False True  
‘%r %r %r %r’ ‘%r %r %r %r’ ‘%r %r %r %r’ ‘%r %r %r %r’  
‘I had this thing.’ ‘That you could type up right.’ “But it didn’t sing.” ‘So I said goodnight.’

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[ex8.py]: http://ex8.py