Python2和Python3中print的用法示例总结

strHello = 'Hello Python'
print strHello
# Hello Python

strHello = "the length of (%s) is %d" %('Hello Wordld', len('Hello World'))
print strHello
# the length of (Hello Wordld) is 11

# 格式 描述
# %% 百分号标记
# %c 字符及其ASCII码
# %s 字符串
# %d 有符号整数(十进制)
# %u 无符号整数(十进制)
# %o 无符号整数(八进制)
# %x 无符号整数(十六进制)
# %X 无符号整数(十六进制大写字符)
# %e 浮点数字(科学计数法)
# %E 浮点数字(科学计数法，用E代替e)
# %f 浮点数字(用小数点符号)
# %g 浮点数字(根据值的大小采用%e或%f)
# %G 浮点数字(类似于%g)
# %p 指针(用十六进制打印值的内存地址)
# %n 存储输出字符的数量放进参数列表的下一个变量中

nHex = 0x20
print 'nHex = %x, nDec = %d, nOct = %o' %(nHex, nHex, nHex)
# nHex = 20, nDec = 32, nOct = 40

# Python 2.7.10 (default, Feb 7 2017, 00:08:15)
# [GCC 4.2.1 Compatible Apple LLVM 8.0.0 (clang-800.0.34)] on darwin
# Type "help", "copyright", "credits" or "license" for more information.
# >>> bin(789)
# '0b1100010101'
# >>>

import math
#default
print 'PI = %f' % math.pi
# PI = 3.141593

# width = 10, precise = 3, align = left
print 'PI = %10.3fxxx' % math.pi
# PI =  3.142xxx

# width = 10, precise = 3, align = right
print 'PI = %-10.3fxxx' % math.pi
# PI = 3.142  xxx

# 前面填充字符串
print 'PI = %06d' % int(math.pi)
# PI = 000003

# precise = 3
print '%.3s' % ('jcodeer')
# jco

# precise = 4
print '%.*s' % (4,'jcodeer')
# jcod

# width = 10, precise = 3
print 'xx%10.3s' % ('jcodeer')
# xx  jco

l = [1, 2, 3, 'jcodeer']
print l
# [1, 2, 3, 'jcodeer']

d = {1: 'A',2: 'B',3: 'C',4: 'D'}
print d
# {1: 'A', 2: 'B', 3: 'C', 4: 'D'}

# print会在行末加上回车，如果不需要，只需在print语句结尾添加一个逗号','
for i in range(0,5):
 print i,
# 0 1 2 3 4

import sys
sys.stdout.write("输出的字符串")

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."
)
# 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.'

import numpy as np
a = np.array([[1,2],[3,4]])
b = np.array([[5,6],[7,8]])
print a
# [[1 2]
# [3 4]]
 
print b
# [[5 6]
# [7 8]]
 
print a, b
# [[1 2]
# [3 4]] [[5 6]
# [7 8]]

# {0}表示第一个元素， {1}表示第二个元素， {2}表示第三个元素，以此类推。。。
 
a = 'Ace'
b = 'hello'
print("{1}, my name is {0}".format(a, b))
# hello, my name is Ace

name = "Ace"
age = 26
print("{myname}'s age is {myage}".format(myname=name, myage=age))
# Ace's age is 26

person = ["Ace", 26]
print("{0[0]}'s age is {0[1]}".format(person))
# Ace's age is 26
  
print("{people[0]}'s age is {people[1]}".format(people=person))
# Ace's age is 26

person = {'Ace': 26}
print("{myname}'s age is {people[Ace]}".format(myname=name,people=person))
# Ace's age is 26

a = 123.456789
haha = 'haha!!!'
print("{0:0.3f}, *{1:<14}*".format(a, haha))
print("{0:0.3f}, *{1:>14}*".format(a, haha))
print("{0:0.3f}, *{1:^14}*".format(a, haha))
print("{0:0.3f}, *{1:}*".format(a, haha))
  
# 123.457, *haha!!!    *
# 123.457, *    haha!!!*
# 123.457, *  haha!!!  *
# 123.457, *haha!!!*