Python[十九]:Standard Library

#Python Standard Library #Output Formattingimport reprlibresult=reprlib.repr(set('supercallingfragmentdocious'))print(result)#:set(['a', 'c', 'd', 'e', 'f', 'g', ...])import pprintt=[[[['black', 'cyan'], 'white', ['green', 'red']], [['magenta','yellow'], 'blue']]]pprint.pprint(t,width=30)#:[[[['black', 'cyan'],#: 'white',#: ['green', 'red']],#: [['magenta', 'yellow'],#: 'blue']]]#The textwrap module formats paragraphs of text to fit a given screen width:import textwrapdoc="""The wrap() method is just like fill() excep it returns a list of strings instead"""print(textwrap.fill(doc,width=20))#:The wrap() method is#:just like fill()#:excep it returns a#:list of strings#:instead#The locale module accesses a database of culture specific data formats. The grouping attribute of locale's format function provides#a direct way of formatting numbers with group separatorsimport localelocale.setlocale(locale.LC_ALL,'English_United States.1252')conv=locale.localeconvx=1234567.8result=locale.format("%d",x,grouping=True)print(result)#result=locale.format("%s%.*f", (conv['currency_symbol'],conv['frac_digits'], x), grouping=True)#print(result)#Templatingfrom string import Templatet=Template('${village}folk send $10 to $cause.')result=t.substitute(village='Beijing',cause='the ditch fund')print(result)t=Template('Retutn the $item to $owner.')d=dict(item='unladen swallow')result=t.safe_substitute(d) #if not fund it will leave placeholder unchangedprint(result)import time,os.pathphotofiles=['img_1074.jpg','img_1076.jpg','img_1077.jpg']class BatchRename(Template): delimiter='%'fmt=input('Enter rename style (%d-date %n-seqnum %f-format):')t=BatchRename(fmt)date=time.strftime('%d%b%y')for i,filename in enumerate(photofiles): base,ext=os.path.splitext(filename) newname=t.substitute(d=date,n=i,f=ext) print('{0} ---> {1}'.format(filename,newname))#Working with Binary Data Record Layoutsimport structdata=open('StandLib1.zip').read()start=0for i in range(3): start+=4 fields=struct.unpack('<IIIHH',data[strat:strat+16]) crc32,comp_size,uncomp_size,filenamesize,extra_size=fields start+=16 filename=data[start:start+filenamesize] start+=filenamesize extra=data[start:start+extra_size] print(filename,hex(crc32),comp_size,uncomp_size) stzrt+=extra_size+comp_size