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I have a text file(dummy.txt) which reads as below:
['abc',1,1,3,3,0,0]
['sdf',3,2,5,1,3,1]
['xyz',0,3,4,1,1,1]
I expect this to be in lists in python as below:
article1 = ['abc',1,1,3,3,0,0]
article2 = ['sdf',3,2,5,1,3,1]
article3 = ['xyz',0,3,4,1,1,1]
That many articles have to be created as many lines present in dummy.txt
I was trying the following things:
Opened the file, split it by '\n' and appended it to an empty list in python, it had extra quotes and square brackets hence tried to use 'ast.literal_eval' which did not work as well.
my_list = []
fvt = open("dummy.txt","r")
for line in fvt.read():
my_list.append(line.split('\n'))
my_list = ast.literal_eval(my_list)
I also tried to manually remove additional quotes and extra square brackets using replace, that did not help me either. Any leads much appreciated.
This should help.
import ast
myLists = []
with open(filename) as infile:
for line in infile: #Iterate Each line
myLists.append(ast.literal_eval(line)) #Convert to python object and append.
print(myLists)
Output:
[['abc', 1, 1, 3, 3, 0, 0], ['sdf', 3, 2, 5, 1, 3, 1], ['xyz', 0, 3, 4, 1, 1, 1]]
fvt.read() will produce the entire file string, so that means line will contain a single character string. So this will not work very well, you also use literal_eval(..) with the entire list of strings, and not a single string.
You can obtain the results by iterating over the file handler, and each time call literal_eval(..) on a single line:
from ast import literal_eval
with open("dummy.txt","r") as f:
my_list = [literal_eval(line) for line in f]
or by using map:
from ast import literal_eval
with open("dummy.txt","r") as f:
my_list = list(map(literal_eval, f))
We then obtain:
>>> my_list
[['abc', 1, 1, 3, 3, 0, 0], ['sdf', 3, 2, 5, 1, 3, 1], ['xyz', 0, 3, 4, 1, 1, 1]]
ast.literal_eval is the right approach. Note that creating a variable number of variables like article1, article2, ... is not a good idea. Use a dictionary instead if your names are meaningful, a list otherwise.
As Willem mentioned in his answer fvt.read() will give you the whole file as one string. It is much easier to exploit the fact that files are iterable line-by-line. Keep the for loop, but get rid of the call to read.
Additionally,
my_list = ast.literal_eval(my_list)
is problematic because a) you evaluate the wrong data structure - you want to evaluate the line, not the list my_list to which you append and b) because you reassign the name my_list, at this point the old my_list is gone.
Consider the following demo. (Replace fake_file with the actual file you are opening.)
>>> from io import StringIO
>>> from ast import literal_eval
>>>
>>> fake_file = StringIO('''['abc',1,1,3,3,0,0]
... ['sdf',3,2,5,1,3,1]
... ['xyz',0,3,4,1,1,1]''')
>>> result = [literal_eval(line) for line in fake_file]
>>> result
[['abc', 1, 1, 3, 3, 0, 0], ['sdf', 3, 2, 5, 1, 3, 1], ['xyz', 0, 3, 4, 1, 1, 1]]
Of course, you could also use a dictionary to hold the evaluated lines:
>>> result = {'article{}'.format(i):literal_eval(line) for i, line in enumerate(fake_file, 1)}
>>> result
{'article2': ['sdf', 3, 2, 5, 1, 3, 1], 'article1': ['abc', 1, 1, 3, 3, 0, 0], 'article3': ['xyz', 0, 3, 4, 1, 1, 1]}
where now you can issue
>>> result['article2']
['sdf', 3, 2, 5, 1, 3, 1]
... but as these names are not very meaningful, I'd just go for the list instead which you can index with 0, 1, 2, ...
When I do this:
import ast
x = '[ "A", 1]'
x = ast.literal_eval(x)
print(x)
I get:
["A", 1]
So, your code should be:
for line in fvt.read():
my_list.append(ast.literal_eval(line))
Try this split (no imports needed) (i recommend):
with open('dummy.txt','r') as f:
l=[i[1:-1].strip().replace("'",'').split(',') for i in f]
Now:
print(l)
Is:
[['abc', 1, 1, 3, 3, 0, 0], ['sdf', 3, 2, 5, 1, 3, 1], ['xyz', 0, 3, 4, 1, 1, 1]]
As expected!!!
I have a problem with the following script because I'm not able to get the full list of items for each line. What I get is something like FreqDist({'be#v': 3, 'have#v': 2, 'get#v': 2, 'publicly#r': 1, 'communicate#v': 1, 'goal#n': 1, 'end#n': 1, 'delight#v': 1, 'prescription#n': 1, 'fertilize#v': 1, ...}), FreqDist({'be#v': 2, 'have#v': 2, 'get#v': 2, '20s#n': 1, 'like#v': 1, 'school#n': 1, 'think#v': 1, 'i#n': 1, 'go#v': 1, 'community#n': 1, ...}), not every word with occurrence 1 is reported.
from nltk import FreqDist
from nltk.tokenize import RegexpTokenizer
tokenizer = RegexpTokenizer('\s+', gaps=True)
m = [FreqDist(tokenizer.tokenize(line)) for line in open('1_tagged_copy.txt')]
print m
Solution: m = [FreqDist(tokenizer.tokenize(line)).items() for line in open('1_tagged_copy.txt')]
Refer to my previous question: How to extract the common words before particular symbol and find particular word
mydict = {"g18_84pp_2A_MVP1_GoodiesT0-HKJ-DFG_MIX-CMVP1_Y1000-MIX.txt" : 0,
"g18_84pp_2A_MVP2_GoodiesT0-HKJ-DFG_MIX-CMVP2_Y1000-MIX.txt" : 1,
"g18_84pp_2A_MVP3_GoodiesT0-HKJ-DFG_MIX-CMVP3_Y1000-MIX.txt" : 2,
"g18_84pp_2A_MVP4_GoodiesT0-HKJ-DFG_MIX-CMVP4_Y1000-MIX.txt" : 3,
"g18_84pp_2A_MVP5_GoodiesT0-HKJ-DFG_MIX-CMVP5_Y1000-MIX.txt" : 4,
"g18_84pp_2A_MVP6_GoodiesT0-HKJ-DFG_MIX-CMVP6_Y1000-MIX.txt" : 5,
"h18_84pp_3A_MVP1_GoodiesT1-HKJ-DFG-CMVP1_Y1000-FIX.txt" : 6,
"g18_84pp_2A_MVP7_GoodiesT0-HKJ-DFG_MIX-CMVP7_Y1000-MIX.txt" : 7,
"h18_84pp_3A_MVP2_GoodiesT1-HKJ-DFG-CMVP2_Y1000-FIX.txt" : 8,
"h18_84pp_3A_MVP3_GoodiesT1-HKJ-DFG-CMVP3_Y1000-FIX.txt" : 9,
"p18_84pp_2B_MVP1_GoodiesT2-HKJ-DFG-CMVP3_Y1000-FIX.txt" : 10}
and I already got my OutputNameDict,
OutputNameDict = {'h18_84pp_3A_MVP_FIX': 1, 'p18_84pp_2B_MVP_FIX': 2, 'g18_84pp_2A_MVP_MIX': 0}
Now what I want to do is to group three new dictionaries by using my common strings CaseNameString(refer to previous question) and values from OutputNameDict.
The idea result will like:
Group1. mydict0 using value 0 in OutputNameDict and string g18_84pp_2A_MVP_GoodiesT0 inCaseNameString.
mydict0 = {"g18_84pp_2A_MVP1_GoodiesT0-HKJ-DFG_MIX-CMVP1_Y1000-MIX.txt" : 0,
"g18_84pp_2A_MVP2_GoodiesT0-HKJ-DFG_MIX-CMVP2_Y1000-MIX.txt" : 1,
"g18_84pp_2A_MVP3_GoodiesT0-HKJ-DFG_MIX-CMVP3_Y1000-MIX.txt" : 2,
"g18_84pp_2A_MVP4_GoodiesT0-HKJ-DFG_MIX-CMVP4_Y1000-MIX.txt" : 3,
"g18_84pp_2A_MVP5_GoodiesT0-HKJ-DFG_MIX-CMVP5_Y1000-MIX.txt" : 4,
"g18_84pp_2A_MVP6_GoodiesT0-HKJ-DFG_MIX-CMVP6_Y1000-MIX.txt" : 5,
"g18_84pp_2A_MVP7_GoodiesT0-HKJ-DFG_MIX-CMVP7_Y1000-MIX.txt" : 6}
Group2. mydict1 using value 1 in OutputNameDict and string h18_84pp_3A_MVP_GoodiesT1 inCaseNameString.
mydict1 ={"h18_84pp_3A_MVP1_GoodiesT1-HKJ-DFG-CMVP1_Y1000-FIX.txt" : 0,
"h18_84pp_3A_MVP2_GoodiesT1-HKJ-DFG-CMVP2_Y1000-FIX.txt" : 1,
"h18_84pp_3A_MVP3_GoodiesT1-HKJ-DFG-CMVP3_Y1000-FIX.txt" : 2}
Group3. mydict2 using value 2 in OutputNameDict and string p18_84pp_2B_MVP_GoodiesT2 inCaseNameString.
mydict2 ={"p18_84pp_2B_MVP1_GoodiesT2-HKJ-DFG-CMVP3_Y1000-FIX.txt" : 0}
Any suggestion? Is there any function to call?
I'd change your OutputNameDict keys to be regular expression patterns, as follows:
OutputNameDict = {'h18_84pp_3A_MVP.*FIX': 1, 'p18_84pp_2B_MVP.*FIX': 2, 'g18_84pp_2A_MVP.*MIX': 0}
Then, using the re regular expression module, use that to match against the keys in mydict, and place the dictionary element into the appropriate key in output_dicts dictionary, as follows
import collections
import re
output_dicts = collections.defaultdict(dict)
for k, v in mydict.iteritems():
for pattern, suffix in OutputNameDict.iteritems():
if re.match(pattern,k):
output_dicts['mydict' + str(suffix)][k] = v
break
else:
output_dicts['not matched'][k] = v
This results in the output_dicts dictionary populated as follows
for k, v in output_dicts.iteritems():
print k
print v
print
Which outputs
mydict1
{'h18_84pp_3A_MVP2_GoodiesT1-HKJ-DFG-CMVP2_Y1000-FIX.txt': 8,
'h18_84pp_3A_MVP3_GoodiesT1-HKJ-DFG-CMVP3_Y1000-FIX.txt': 9,
'h18_84pp_3A_MVP1_GoodiesT1-HKJ-DFG-CMVP1_Y1000-FIX.txt': 6}
mydict0
{'g18_84pp_2A_MVP1_GoodiesT0-HKJ-DFG_MIX-CMVP1_Y1000-MIX.txt': 0,
'g18_84pp_2A_MVP2_GoodiesT0-HKJ-DFG_MIX-CMVP2_Y1000-MIX.txt': 1,
'g18_84pp_2A_MVP4_GoodiesT0-HKJ-DFG_MIX-CMVP4_Y1000-MIX.txt': 3,
'g18_84pp_2A_MVP5_GoodiesT0-HKJ-DFG_MIX-CMVP5_Y1000-MIX.txt': 4,
'g18_84pp_2A_MVP3_GoodiesT0-HKJ-DFG_MIX-CMVP3_Y1000-MIX.txt': 2,
'g18_84pp_2A_MVP6_GoodiesT0-HKJ-DFG_MIX-CMVP6_Y1000-MIX.txt': 5,
'g18_84pp_2A_MVP7_GoodiesT0-HKJ-DFG_MIX-CMVP7_Y1000-MIX.txt': 7}
mydict2
{'p18_84pp_2B_MVP1_GoodiesT2-HKJ-DFG-CMVP3_Y1000-FIX.txt': 10}
IF I have a dictionary:
mydict = {"g18_84pp_2A_MVP1_GoodiesT0-HKJ-DFG_MIX-CMVP1_Y1000-MIX.txt" : 0,
"g18_84pp_2A_MVP2_GoodiesT0-HKJ-DFG_MIX-CMVP2_Y1000-MIX.txt" : 1,
"g18_84pp_2A_MVP3_GoodiesT0-HKJ-DFG_MIX-CMVP3_Y1000-MIX.txt" : 2,
"g18_84pp_2A_MVP4_GoodiesT0-HKJ-DFG_MIX-CMVP4_Y1000-MIX.txt" : 3,
"g18_84pp_2A_MVP5_GoodiesT0-HKJ-DFG_MIX-CMVP5_Y1000-MIX.txt" : 4,
"g18_84pp_2A_MVP6_GoodiesT0-HKJ-DFG_MIX-CMVP6_Y1000-MIX.txt" : 5,
"h18_84pp_3A_MVP1_GoodiesT1-HKJ-DFG-CMVP1_Y1000-FIX.txt" : 6,
"g18_84pp_2A_MVP7_GoodiesT0-HKJ-DFG_MIX-CMVP7_Y1000-MIX.txt" : 7,
"h18_84pp_3A_MVP2_GoodiesT1-HKJ-DFG-CMVP2_Y1000-FIX.txt" : 8,
"h18_84pp_3A_MVP3_GoodiesT1-HKJ-DFG-CMVP3_Y1000-FIX.txt" : 9,
"p18_84pp_2B_MVP1_GoodiesT2-HKJ-DFG-CMVP3_Y1000-FIX.txt" : 10}
I want to extract the common part g18_84pp_2A_MVP_GoodiesT0 before the first -.
also I want add a _MIX to follow g18_84pp_2A_MVP_GoodiesT0 when finding the particular word MIX in first group . Assume that I am able to classify two groups depending on whether is MIX or FIX in myDict, then the final Output dictionary:
OutputNameDict= {"g18_84pp_2A_MVP_GoodiesT0_MIX" : 0,
"h18_84pp_3A_MVP_GoodiesT1_FIX" : 1,
"p18_84pp_2B_MVP_FIX": 2}
Is there any function I could use to find common part? How pick up the word before or after particular symbol like - and find particular words like MIX or FIX?
You can use split to get the common part:
s = "g18_84pp_2A_MVP1_GoodiesT0-HKJ-DFG_MIX-CMVP1_Y1000-MIX.txt"
n = s.split('-')[0]
In fact, split will give you a list of each token delimited by '-', so s.split('-') yields:
['g18_84pp_2A_MVP1_GoodiesT0', 'HKJ', 'DFG_MIX', 'CMVP1_Y1000', 'MIX.txt']
To see if MIX or FIX is in a string, you can use in:
if 'MIX' in s:
print "then MIX is in the string s"
If you want to get rid if the numbers after 'MVP', you can use re module:
import re
s = 'g18_84pp_2A_MVP1_GoodiesT0'
s = re.sub('MVP[0-9]*','MVP',s)
Here is a sample function to get a list of the common parts:
def foo(mydict):
return [re.sub('MVP[0-9]*', 'MVP', k.split('-')[0]) for k in mydict]
You can use the index() function to find your dashes, then with that knowledge you can take the rest of the string past that point. For instance,
mydict = {"g18_84pp_2A_MVP1_GoodiesT0-HKJ-DFG_MIX-CMVP1_Y1000-MIX.txt" : 0,
"g18_84pp_2A_MVP2_GoodiesT0-HKJ-DFG_MIX-CMVP2_Y1000-MIX.txt" : 1,
"g18_84pp_2A_MVP3_GoodiesT0-HKJ-DFG_MIX-CMVP3_Y1000-MIX.txt" : 2,
"g18_84pp_2A_MVP4_GoodiesT0-HKJ-DFG_MIX-CMVP4_Y1000-MIX.txt" : 3,
"g18_84pp_2A_MVP5_GoodiesT0-HKJ-DFG_MIX-CMVP5_Y1000-MIX.txt" : 4,
"g18_84pp_2A_MVP6_GoodiesT0-HKJ-DFG_MIX-CMVP6_Y1000-MIX.txt" : 5,
"g18_84pp_2A_MVP7_GoodiesT0-HKJ-DFG_MIX-CMVP7_Y1000-MIX.txt" : 6,
"h18_84pp_3A_MVP1_GoodiesT1-HKJ-DFG_MIX-CMVP1_Y1000-FIX.txt" : 7,
"h18_84pp_3A_MVP2_GoodiesT1-HKJ-DFG_MIX-CMVP2_Y1000-FIX.txt" : 8,
"h18_84pp_3A_MVP2_GoodiesT1-HKJ-DFG_MIX-CMVP3_Y1000-FIX.txt" : 9}
for value in sorted(mydict.iterkeys()):
index = value.index('-')
extracted = value[index+1:-4] # Goes past the first occurrence of - and removes .txt from the end
print extracted[-3:] # Find the last 3 letters in the string
Will print the following:
MIX
MIX
MIX
MIX
MIX
MIX
MIX
FIX
FIX
FIX
Then if statements can be used to do what you would like.
If you want to extract just the common part.
index = value.index('-')
extracted = value[:index] # Will get g18_84pp_2A_MVP1_GoodiesT0
Then to figure out the ending to use. If you know the ending of the mydict value will always be MIX.txt or FIX.txt then you can do this.
for value in sorted(mydict.iterkeys()):
ending = value[-7:-4]
index = value.index('-')
extracted = value[:index]
print "%s_%s" % (extracted, ending)
Which prints
g18_84pp_2A_MVP1_GoodiesT0_MIX
g18_84pp_2A_MVP2_GoodiesT0_MIX
g18_84pp_2A_MVP3_GoodiesT0_MIX
g18_84pp_2A_MVP4_GoodiesT0_MIX
g18_84pp_2A_MVP5_GoodiesT0_MIX
g18_84pp_2A_MVP6_GoodiesT0_MIX
g18_84pp_2A_MVP7_GoodiesT0_MIX
h18_84pp_3A_MVP1_GoodiesT1_FIX
h18_84pp_3A_MVP2_GoodiesT1_FIX
h18_84pp_3A_MVP2_GoodiesT1_FIX
Then you add it to the extracted dictionary.
Thanks for the answers. My complete code as following. Any suggestion to optimize it?
import re
mydict = {"g18_84pp_2A_MVP1_GoodiesT0-HKJ-DFG_MIX-CMVP1_Y1000-MIX.txt" : 0,
"g18_84pp_2A_MVP2_GoodiesT0-HKJ-DFG_MIX-CMVP2_Y1000-MIX.txt" : 1,
"g18_84pp_2A_MVP3_GoodiesT0-HKJ-DFG_MIX-CMVP3_Y1000-MIX.txt" : 2,
"g18_84pp_2A_MVP4_GoodiesT0-HKJ-DFG_MIX-CMVP4_Y1000-MIX.txt" : 3,
"g18_84pp_2A_MVP5_GoodiesT0-HKJ-DFG_MIX-CMVP5_Y1000-MIX.txt" : 4,
"g18_84pp_2A_MVP6_GoodiesT0-HKJ-DFG_MIX-CMVP6_Y1000-MIX.txt" : 5,
"h18_84pp_3A_MVP1_GoodiesT1-HKJ-DFG-CMVP1_Y1000-FIX.txt" : 6,
"g18_84pp_2A_MVP7_GoodiesT0-HKJ-DFG_MIX-CMVP7_Y1000-MIX.txt" : 7,
"h18_84pp_3A_MVP2_GoodiesT1-HKJ-DFG-CMVP2_Y1000-FIX.txt" : 8,
"h18_84pp_3A_MVP3_GoodiesT1-HKJ-DFG-CMVP3_Y1000-FIX.txt" : 9,
"p18_84pp_2B_MVP1_GoodiesT2-HKJ-DFG-CMVP3_Y1000-FIX.txt" : 10}
ExtractDict = {}
start = 0
for stringList in sorted(mydict.iterkeys()):
stringList = stringList.split('.')[0]
underscore = stringList.split('_')
Area= re.split('[0-9]+',stringList.split('_')[3])[0] # MVP and etc.
CaseNameString=underscore[0]+"_"+underscore[1]+"_"+underscore[2]+"_"+Area #g18_84pp_2A_MVP_GoodiesT0 and etc.
postfix= stringList.split('-')[4]
Newstring= CaseNameString + "_" + postfix
ExtractDict[Newstring]= start
start += 1
startagain =0
OutputNameDict = {}
for OutputNameList in sorted(ExtractDict.iterkeys()):
OutputNameDict[OutputNameList] = startagain
startagain +=1
#OutputNameDict = {'h18_84pp_3A_MVP_FIX': 1, 'p18_84pp_2B_MVP_FIX': 2, 'g18_84pp_2A_MVP_MIX': 0}
Trying to have a user input their name, copy that variable to a file, and then read it back. However, when read back, it only says [][]
My code looks like this (currently)
Name = raw_input("What is your Name? ")
print "you entered ", Name
fo = open("foo.txt", "r+")
fo.write (Name)
str = fo.read();
print "Read String is : ", str
fo.close()
When I look at the foo.txt file, it has all of this inside:
Mathew” ÿÿÿÿ _getresponse:16: thread woke up: response: ('OK', {'maybesave': 1, 'format': 1, 'runit': 1, 'remove_selection': 1, 'str': 1, '_file_line_helper': 1, '_asktabwidth': 1, '_filename_to_unicode': 1, 'open_stack_viewer': 1, 'get_region': 1, 'cut': 1, 'open_module': 1, 'showerror': 1, 'class': 1, 'smart_indent_event': 1, 'set_status_bar': 1, 'about_dialog': 1, 'indent_region_event': 1, 'load_extension': 1, 'set_region': 1, '_close': 1, 'cancel_callback': 1, 'postwindowsmenu': 1, 'subclasshook': 1, 'newline_and_indent_event': 1, 'toggle_debugger': 1, 'saved_change_hook': 1, 'eof_callback': 1, 'get_warning_stream': 1, 'get_standard_extension_names': 1, 'guess_indent': 1, 'ResetFont': 1, 'center_insert_event': 1, 'replace_event': 1, 'unload_extensions': 1, 'del_word_right': 1, 'close_debugger': 1, 'EditorWindow_extra_help_callback': 1, 'python_docs': 1, 'fill_menus': 1, 'flush': 1, 'close': 1, 'setattr': 1, 'set_notabs_indentwidth': 1, 'help_dialog': 1, 'set_saved': 1, 'get_selection_indices': 1, 'open_debugger': 1, 'tabify_region_event': 1, 'comment_region_event': 1, 'get_var_obj': 1, 'find_selection_event': 1, '_rmcolorizer': 1, 'goto_line_event': 1, 'load_standard_extensions': 1, 'reset_undo': 1, 'long_title': 1, 'paste': 1, 'close2': 1, 'reset_help_menu_entries': 1, 'set_indentation_params': 1, 'open_class_browser': 1, 'endexecuting': 1, 'delattr': 1, '_addcolorizer': 1, 'repr': 1, 'close_hook': 1, 'home_callback': 1, 'right_menu_event': 1, 'getlineno': 1, 'apply_bindings': 1, 'restart_shell': 1, '_make_blanks': 1, 'get_geometry': 1, 'ApplyKeybindings': 1, 'get_tabwidth': 1, 'ResetColorizer': 1, 'open_path_browser': 1, 'filename_change_hook': 1, '_build_char_in_string_func': 1, 'isatty': 1, 'find_event': 1, 'untabify_region_event': 1, 'reduce': 1, 'find_in_files_event': 1, 'new_callback': 1, 'getvar': 1, 'copy': 1, 'center': 1, 'writelines': 1, 'recall': 1, 'load_extensions': 1, 'showprompt': 1, 'close_event': 1, 'reindent_to': 1, 'askinteger': 1, 'hash': 1, 'RemoveKeybindings': 1, 'dedent_region_event': 1, 'linefeed_callback': 1, 'is_char_in_string': 1, 'getattribute': 1, 'move_at_edge_if_selection': 1, 'beginexecuting': 1, 'enter_callback': 1, 'short_title': 1, 'getwindowlines': 1, 'smart_backspace_event': 1, 'sizeof': 1, 'set_tabwidth': 1, 'find_again_event': 1, 'init': 1, 'del_word_left': 1, 'get_saved': 1, 'reduce_ex': 1, 'new': 1, 'select_all': 1, 'gotoline': 1, 'view_restart_mark': 1, 'change_indentwidth_event': 1, 'write': 1, 'set_debugger_indicator': 1, 'config_dialog': 1, 'set_warning_stream': 1, 'setvar': 1, 'createmenubar': 1, 'begin': 1, 'toggle_tabs_event': 1, 'askyesno': 1, 'ispythonsource': 1, 'resetoutput': 1, 'set_close_hook': 1, 'goto_file_line': 1, 'readline': 1, 'toggle_jit_stack_viewer': 1, 'make_rmenu': 1, 'EditorWindow_recent_file_callback': 1, 'uncomment_region_event': 1, 'update_recent_files_list': 1, 'set_line_and_column': 1}) ã èã”po” èã”po”
Any idea why?
First, you've opened the file in mode "r+" which is read-write. This will not empty the file, and anything you write will overwrite existing bytes. This is almost certainly not what you want: either 'a' if you want to append to the file, or 'w' if you want to delete the file first if it already exists.
Second, you're reading from where the write left off, and not repositioning the file cursor. In fact it's slightly worse than that: behavior of file objects isn't very well defined if you don't seek between reads and writes.
From C reference for fopen
For the modes where both read and writing (or appending) are allowed
(those which include a "+" sign), the stream should be flushed
(fflush) or repositioned (fseek, fsetpos, rewind) between either a
reading operation followed by a writing operation or a writing
operation followed by a reading operation.
The Python reference makes it clear that open() is implemented using standard C file objects.
Here's what I would write:
with open('foo.txt', 'w') as f:
f.write(name)
with open('foo.txt', 'r') as f:
print 'Text is:', f.read()
The with statement is nice here as it automatically closes the file once the write is done. By closing the file and reopening it in read mode, you guarantee that the written text made it into the file and isn't being cached.
As for why you get nothing back, that's probably because you have to seek to the beginning first:
fo.seek(0)
result = fo.read()
There is a pointer which marks the "current" position in a file. When you open a file, it is set at the beginning of the file. Next thing you do is write to it. As you write, the pointer keeps advancing. When you have written completely, the pointer is at the end of the file. And if you start reading then (which is what you are doing here), you'll get nothing but junk. So, you need to reset the pointer to the beginning before you start reading which can be done by seek as you can see above or you can close the file after writing and open it again before reading.
Name = raw_input("What is your Name? ")
print "you entered ", Name
fo = open("foo.txt", "r+")
fo.write (Name)
fo.flush()
fo.close()
fo = open("foo.txt", "r+")
str = fo.read();
print "Read String is : ", str
fo.close()
It is also a good idea to call flush() after writing to the file.