Python print函数用法,print 格式化输出
原文地址:http://blog.csdn.net/zanfeng/article/details/52164124 / https://www.cnblogs.com/hokky/p/8434236.html
使用print输出各型的
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字符串
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整数
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浮点数
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出度及精度控制
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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,
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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
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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 |
如果需要输出二进制的话,可以使用python函数 bin()
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Python 2.7 . 6 (default, Nov 10 2013 , 19 : 24 : 18 ) [MSC v. 1500 32 bit (Intel)] on win 32 Type "help" , "copyright" , "credits" or "license" for more information. >>> bin ( 789 ) '0b1100010101' >>> |
3.格式化输出浮点数(float)
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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)
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#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)
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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。
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for i in range ( 0 , 5 ): print i, |
或直接使用下面的函数进行输出:
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sys.stdout.write( "输出的字串" ) |
7. 万能的 %r
有个同事问我python里面print ”%r” 是什么用途,被问倒了。
用了这么些年的python,还没用过print %r。
网上查了一下,发现%r是一个万能的格式付,它会将后面给的参数原样打印出来,带有类型信息。
python print %r 案例
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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:
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$ 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.' $ |