print "{:.2f}".format(3.1415926) #3.14,保留小数点后两位
print "{:+.2f}".format(3.1415926) #+3.14 带符号保留小数点后两位
print "{:+.2f}".format(-10) #-10.00 带符号保留小数点后两位
print "{:+.0f}".format(-10.00) #-10 不带小数
print "{:0>2d}".format(1) #01 数字补零 (填充左边, 宽度为2)
print "{:x<2d}".format(1) #1x 数字补x (填充右边, 宽度为4)
print "{:x<4d}".format(10) #10xx 数字补x (填充右边, 宽度为4)
print "{:,}".format(1000000) #1,000,000 以逗号分隔的数字格式
print "{:.2%}".format(0.12) #12.00% 百分比格式
print "{:.2e}".format(1000000) #1.00e+06 指数记法
print "{:<10d}".format(10) #10 左对齐 (宽度为10)
print "{:>10d}".format(10) #  10 右对齐 (默认, 宽度为10)
print "{:^10d}".format(10) # 10 中间对齐 (宽度为10)

def format(self, *args, **kwargs): # known special case of str.format
  """
  S.format(*args, **kwargs) -> string

  Return a formatted version of S, using substitutions from args and kwargs.
  The substitutions are identified by braces ('{' and '}').
  """
  pass

print "{0} and {1} is good for big data".format("python","java")
print "{} and {} is good for big data".format("python","java")
print "{1} and {0} and {0} is good for big data".format("python","java")

python and java is good for big data
python and java is good for big data
java and python and python is good for big data

print "{language1} is as well as {language2}".format(language1="python",language2="java")

python is as well as java

languages = ["python","java"]
print "{0[0]} is as well as {0[1]}".format(languages)

python is as well as java

class Person(object):
 def __init__(self,name,age):
  self.name = name
  self.age = age

 def __str__(self):
  return "name is: {current.name}, age is: {current.age}".format(current=self)

p = Person("leilei",18)
print p

name is: leilei, age is: 18