Python Exercises (ii)

1. Sort a list of numbers from small to large, then write to the file, then read the contents of the file from the file, and then reverse-order it in the next line appended to the file.

import codecsl1=[22,32,5,88,43,20,18,99,201,100,302]l2=[]print  ' ********** sort ********** ' L1.sort () print l1print  ' ********** write file.txt file ********** ' With codecs.open (' file.txt ', ' w+ ')  as  F1: for i in xrange (0,len (L1)):     if i<len (L1) -1:         f1.write (str (l1[i]) + ', ')     else:         f1.write (str (l1[i))         print  ' Write file Success!!! ' With codecs.open (' file.txt ', ' r+ ')  as f2: l2=f2.read (). Split (', ') print  ' ********** reverse order * ' L2.reverse () print l2print  ' ********** inserts the reverse order result into the file.txt file ********** ' With codecs.open (' File.txt ', ' a ')  as f3:    f3.write (' \ n ')     for x  In xrange (0,len (L2)):      if x<len (L2) -1:         f3.write (l2[x]+ ', ')      else:         F3.write (l2[x])         print  ' Write file successfully!!! ‘

Operation Result:

Sort **********[5, 18, 20, 22, 32, 43, 88, 99, 100, 201, 302]********** write file.txt file ********** write file success!!! Reverse order **********[' 302 ', ' 201 ', ' 100 ', ' 99 ', ' 88 ', ' 43 ', ' 32 ', ' 22 ', ' 20 ', ' 18 ', ' 5 ']********** insert the reverse order result into the file.txt file * * * Write file Success!!! 5,18,20,22,32,43,88,99,100,201,302302,201,100,99,88,43,32,22,20,18,5

2. Write the string, list, tuple, dict to the file, respectively.

Import codecsstr= ' this is a string,now insert into the file.txt ' L1=[' This ', ' was ', ' a ', ' String ']t1= (' Insert ', ' into ', ' the ', ' file.txt ') d1={' Name ': ' File ', ' Type ': ' txt ', ' Context ': ' Dict '} With codecs.open (' file.txt ', ' a ')  as f1:    f1.write (' \ n ')      print  ' ******** write String ******** '     f1.write (str)     f1.write ( ' \ n ')     print  ' ******** start writing to list ******** '     for x in  xrange (0, len (L1)):      if x<len (L1) -1:         f1.write (l1[x]+ ', ')     else:             f1.write (L1[x])              print  ' Write list success!!! '     f1.write (' \ n ')     print  ' ******** start writing tuples ********'     for y in xrange (0, len (T1)):         if y<len (T1) -1:             F1.write (t1[y]+ ', ')         else:             f1.write (T1[y])              print  ' write meta-group success!!! '     f1.write (' \ n ')     print  ' ******** start writing dictionary ******** '      for z in d1.iteritems ():         for a  in z:              f1.write (A + '   ')     print  ' Write dictionary success!!! ‘

Operation Result:

Write String **************** start write list ******** write list success!!! Start writing tuples ******** write tuples successfully!!! Start writing dictionary ******** write dictionary success!!! This was a string,now insert into the file.txtthis,is,a,stringinsert,into,the,file.txttype txt Name file Context dict

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Python Exercises (ii)