--Notes：
测试环境：Windows ，python 2.7.3，python 自带的IDLE
#-*- coding: utf-8 -*-
# First Lesson
# --- Line syntax ---
# The comment character is "#" ;comments are terminated by end of line.
# Long lines may be continued by ending the line with a backslash().
# --- Names and Keywords ---
# Python names(also called identifiers) can be any length and follow these rules:
# 1.The first or only character must be a letter(uppercase or lowercase) or the underbar character,"_".
# 2.Any additional characters may be letters,underbar,or digits.
# 3.Case is significant in Python. The name "Robin" is not the same name as "robin".
#
# The names below are keywords,also known as reserved words.They have special meaning in Python
# and cannot be used as names or identifiers.
#
# and as assert break class continue def del elif else except exec finally for from global
# import if in is lambda not or pass print raise return try with while yield
#
# --- Python's common types ---
# int : 3; long: 3L ; bool: True,False; float : 3.1425
# complex :(3.2+4j) ; str :'string'; unicode :u'Fred';
# list :[] ; tuple:(); dict:{}; bytearray('Bletchley')
# file open('/etc/motd')
#
# To write a long-type constant ,use the same syntax as for int-type constants,
# but place a letter L immediately after the last digit.Also, if an operation on
# int values results in a number too large to reparesent as an int, Python will
# automatically converted it to type long.
#page 16
# --- Methods on Str values ---
##These methods are availabe on any string value S.
##S.capitalize()
##Return S with its first character capitalized(if a letter).
##print 'e e cummings'.capitalize()
##print '2 e 3cummings'.capitalize()
##print 'word in cummings'.capitalize()
##S.center(w)
##Return S centered in a string of width w,padded with spaces.
##If w<=len(S),the result is a copy of S. If the number of padding is
##odd ,the extra space will placed after the centered value.
##print 'x'.center(4)
##print 'x'.center(5)
##print 'capitalize'.center(4)
##S.count(t[,start[,end]])
##Return the number of times string t occurs in S. To search on a
##slice S[start:end] of S,supply start and end arguments.
##print 'banana'.count('a')
##print 'banana'.count('na')
##print 'banana'.count('a',3)
##print 'banana'.count('a',3,5)
##print '中华人民共和国'.count('民')
##print '黄山落叶松叶落山黄'.count('黄')
##S.decode(encoding)
##If S contains an encodedd Unicode String ,this method will return the corresponding
##value as unicode type. The encoding argument specifies which decoder to use;
##typically this will be the string 'utf_8' for the UTF-8 encoding.
##s=u'banana';
##print s.decode('utf-8')
##print s.decode('gbk')
##print s.decode('GBK')
##S.endswith(t[,start[,end]])
##Predicate to test whether S ends with String t.If you supply the optional start
##and end arguments,it tests whether the slice S[start:end] ends with t.
##s='落霞与孤鹜齐飞，秋水共长天一色'
##print s.endswith('秋水')
##print s.endswith('色')
##print s.endswith('一色')
##print s.endswith('秋水共长天一色')
##print s
##print s[1:7]
##print s.endswith('齐飞',1,7)
##s='Python is not su grace!'
##print s
##print s[1:9]
##print s.endswith('is',1,9)
##
##输出：
##False
##True
##True
##True
##落霞与孤鹜齐飞，秋水共长天一色
##惤闇炰
##False
##Python is not su grace!
##ython is
##True
##s.expandtabs([tabsize])
##Returns a copy of s with all tabs repalced by one of more spaces.
##Each tab is interpareted as a request to move to the next "tab stop".
##The optional tabsize argument specifies the number of sapces
##between tab stops;the defualt is 8.
##s.find(t[,satrt[,end]])
##If string t is not found in S,return -1; otherwise return the index of the
##first position in s that matches t.
##The optional start and end arguments restrict the search to slice s[start:end].
##s.index(t[,start[,end]])
##Works like .find(),but if t is not found,it raise a ValueError exception.
##s.isalum()
##predicate that tests whether S is nonempty and all its characters are alphanumeric.
##s.isalpha()
##Predicate that tests whether s is nonempty and all its characters are letters.
##s.isdigit()
##Predicate that tests whether s is nonempty and all its characters are digits.
##s.islower()
##Predicate that tests whether s is nonempty and all its letters are lowercase
##(non-letter characters are ignored).
##s.isspace()
##Predicate that tests whether s is nonempty and all its characters are whitespace characters.
##'
'.isspace()
##s.istitle()
##A predicate that tests whether s has "title case".
##s.isupper()
##Predicate that tests whether s is nonempty and all its letters are uppercase letters
##(non-letter cahr-acters are ignored).
s.join(L)
L must be an iterable that produces a sequence of strings.The returned value is a string
containing the members of the sequence with copies of the delimiter string s inserted between them.
s.ljust(w)
Return a copy of s left-justified in a field of width w,padded with spaces.If w<=len(s),
the result is a copy of s.
s.lower()
Returns a copy of S with all uppercase letters replaced by their lowercase equivalent.
s.lstrip([c])
Return s with all leading characters from string c removed.The default value for c is a string
containing all the whitespace characters.