python 文件插入第一行
def file_insert(fname,linenos=[],strings=[]): """ Insert several strings to lines with linenos repectively. The elements in linenos must be in increasing order and len(strings) must be equal to or less than len(linenos). The extra lines ( if len(linenos)> len(strings)) will be inserted with blank line. """ if os.path.exists(fname): lineno = 0 i = 0 for line in fileinput.input(fname,inplace=1): # inplace must be set to 1 # it will redirect stdout to the input file lineno += 1 line = line.strip() if i<len(linenos) and linenos[i]==lineno: if i>=len(strings): print "\n",line else: print strings[i] print line i += 1 else: print line
?fileinput.input的inplace必须要设为1，以便让stdout被重定向到输入文件里：
file_insert('a.txt',[1,4,5],['insert1','insert4']
?
