Re: generating unique variable name via loops
4 Kasım 2014 Salı 13:29:34 UTC+2 tarihinde Fatih Güven yazdı: Editted: Grammar revision. Hi, I want to generate a unique variable name for list using python. list1=... list2=... . . . listx=... where x is a number. You can remember it from saving a file in a directory. If you have already created a new file, save dialog suggest that new file is already exist, do you want to save it as new file (1)? so I want to apply it for list names. Do you have any idea about this. -- https://mail.python.org/mailman/listinfo/python-list
Re: generating unique variable name via loops
Fatih Güven wrote:
I want to generate a unique variable name for list using python.
list1=...
list2=...
.
.
.
listx=... where x is a number.
You can remember it from saving a file in a directory. If you have already
created a new file, save dialog sugget that new file is already
exist, do you want to save it as new file (1)? so I want to apply it
for list names.
Do you any idea about this.
Do you really want to use
list1, list2, list3, ... as variable names? You shouldn't. Instead use a
dict or a list of lists:
list_of_lists = []
list_of_lists.append([1, 2, 3])
list_of_lists.append([a, b, c])
list_of_lists.append([foo, bar, baz])
You can then access the second list with
letters = list_of_lists[1]
print(letters)
['a', 'b', 'c']
On the other hand if you just want to generate names an easy to understand
approach is to increment a global variable every time you invoke the name-
generating function:
_index = 1
def next_name():
... global _index
... name = list{}.format(_index)
... _index += 1
... return name
...
next_name()
'list1'
next_name()
'list2'
next_name()
'list3'
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Re: generating unique variable name via loops
Fatih Güven wrote: 4 Kas?m 2014 Sal? 13:29:34 UTC+2 tarihinde Fatih Güven yazd?: I want to generate a unique variable name for list using python. list1=... list2=... for x in range(1,10): exec(list%d = [] % x) -- https://mail.python.org/mailman/listinfo/python-list
Re: generating unique variable name via loops
Veek M wrote: Fatih Güven wrote: 4 Kas?m 2014 Sal? 13:29:34 UTC+2 tarihinde Fatih Güven yazd?: I want to generate a unique variable name for list using python. list1=... list2=... for x in range(1,10): exec(list%d = [] % x) Why would you do this? -- https://mail.python.org/mailman/listinfo/python-list
Re: generating unique variable name via loops
4 Kasım 2014 Salı 15:19:20 UTC+2 tarihinde Veek M yazdı: Fatih Güven wrote: 4 Kas?m 2014 Sal? 13:29:34 UTC+2 tarihinde Fatih Güven yazd?: I want to generate a unique variable name for list using python. list1=... list2=... for x in range(1,10): exec(list%d = [] % x) This is okay but i can't use the method .append for example list1.append(abc) -- https://mail.python.org/mailman/listinfo/python-list
Re: generating unique variable name via loops
4 Kasım 2014 Salı 15:37:59 UTC+2 tarihinde Peter Otten yazdı: Veek M wrote: Fatih Güven wrote: 4 Kas?m 2014 Sal? 13:29:34 UTC+2 tarihinde Fatih Güven yazd?: I want to generate a unique variable name for list using python. list1=... list2=... for x in range(1,10): exec(list%d = [] % x) Why would you do this? I have a structured and repetitive data. I want to read a .txt file line by line and classified it to call easily. For example employee1 has a name, a salary, shift, age etc. and employee2 and other 101 employee have all of it. Call employee1.name or employee2.salary and assign it to a new variable, something etc. -- https://mail.python.org/mailman/listinfo/python-list
Re: generating unique variable name via loops
Fatih Güven wrote: This is okay but i can't use the method .append for example list1.append(abc) works for me -- https://mail.python.org/mailman/listinfo/python-list
Re: generating unique variable name via loops
- Original Message -
From: Fatih Güven mfthgu...@gmail.com
I have a structured and repetitive data. I want to read a .txt file
line by line and classified it to call easily. For example employee1
has a name, a salary, shift, age etc. and employee2 and other 101
employee have all of it.
Call employee1.name or employee2.salary and assign it to a new
variable, something etc.
Some python 2.7 pseudo code to give you some leads
employes = {}
with open('file.txt') as f_:
for line in f_:
name, age, phone = line.split(',')
employes[name] = (age, phone)
print employes
If your file is a csv format, it could even be easier using the csv module.
JM
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privileged. If you are not the intended recipient, please notify the sender
immediately and do not disclose the contents to any other person, use it for
any purpose, or store or copy the information in any medium. Thank you.
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Re: generating unique variable name via loops
Fatih Güven wrote:
4 Kasım 2014 Salı 15:37:59 UTC+2 tarihinde Peter Otten yazdı:
Veek M wrote:
Fatih Güven wrote:
4 Kas?m 2014 Sal? 13:29:34 UTC+2 tarihinde Fatih Güven yazd?:
I want to generate a unique variable name for list using python.
list1=...
list2=...
for x in range(1,10):
exec(list%d = [] % x)
Why would you do this?
I have a structured and repetitive data.
I was actually asking Veek M.
I want to read a .txt file line
by line and classified it to call easily. For example employee1 has a
name, a salary, shift, age etc. and employee2 and other 101 employee have
all of it.
Call employee1.name or employee2.salary and assign it to a new variable,
something etc.
I can only repeat my previous advice. Instead of creating variables for
employee1, employee2, and so on make a list of employees:
$ cat employees.txt
Peter,3000
Paul,2000
Mary,1000
$ cat employees.py
#!/usr/bin/env python3
import csv
class Employee:
def __init__(self, name, salary):
self.name = name
self.salary = salary
if __name__ == __main__:
employees = []
with open(employees.txt) as f:
for row in csv.reader(f):
employees.append(Employee(row[0], int(row[1])))
for employee in employees:
print(employee.name, -- salary:, employee.salary, doubloons)
$ python3 employees.py
Peter -- salary: 3000 doubloons
Paul -- salary: 2000 doubloons
Mary -- salary: 1000 doubloons
You wouldn't want to reference Paul as employee2 -- what if the order in the
text file changed? Instead you can make a dict that maps name to employee...
employees_by_name = {}
for employee in employees:
name = employee.name
if name in employees_by_name:
raise ValueError(duplicate name {}.format(name))
employees_by_name[name] = employee
and use that dict to look up an employee:
while True:
name = input(enter a name )
if name == :
print(That's all folks)
break
if name not in employees_by_name:
print(unknown name)
else:
print(Salary:, employees_by_name[name].salary, doubloons)
$ python3 employees.py
Peter -- salary: 3000 doubloons
Paul -- salary: 2000 doubloons
Mary -- salary: 1000 doubloons
enter a name Peter
Salary: 3000 doubloons
enter a name Mary
Salary: 1000 doubloons
enter a name paul
unknown name
enter a name Paul
Salary: 2000 doubloons
enter a name
That's all folks
$
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Re: generating unique variable name via loops
Hi-
Questions like this appear so often in various places (mailing lists,
forums, sites like Stack Overflow) that I think a very blunt/candid
answer is appropriate. This is especially true since there's always
someone who responds to the question as-is with some monstrosity of
exec() and string formatting, instead of addressing the underlying issue
of using the right data structure for what you're trying to accomplish.
On 11/04/2014 06:29 AM, Fatih Güven wrote:
I want to generate a unique variable name for list using python.
list1=...
list2=...
.
.
.
listx=... where x is a number.
*Incorrect.* You do not want to do this. You think you do, but that's
presumably because you aren't familiar with common data structures that
are available in Python. As Peter Otten said, this is *exactly* the
right situation to use a list.
You mentioned having structured and repetitive data, wanting to read a
.txt file and process each line, and wanting to access each employee's
data as appropriate. The general structure of this would be
employees = []
with open('employee_data.txt') as f:
... for line in f:
... # parse_line here isn't anything standard or built-in, it's
... # what you would write to transform a line of the data
... # file into whatever object you're interested in with
... # 'name', 'salary', etc. attributes
... employee = parse_line(line)
... employees.append(employee)
...
employees[0].salary
15
Your line1 is now employees[0] and so on. Now, you can *easily* answer
questions like what's the total salary of all employees?
total = 0
for employee in employees:
... total += employee.salary
...
total
7502000
(or 'sum(employee.salary for employee in employees)' of course.)
MMR...
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Re: generating unique variable name via loops
4 Kasım 2014 Salı 17:01:17 UTC+2 tarihinde Peter Otten yazdı:
Fatih Güven wrote:
4 Kasım 2014 Salı 15:37:59 UTC+2 tarihinde Peter Otten yazdı:
Veek M wrote:
Fatih Güven wrote:
4 Kas?m 2014 Sal? 13:29:34 UTC+2 tarihinde Fatih Güven yazd?:
I want to generate a unique variable name for list using python.
list1=...
list2=...
for x in range(1,10):
exec(list%d = [] % x)
Why would you do this?
I have a structured and repetitive data.
I was actually asking Veek M.
I want to read a .txt file line
by line and classified it to call easily. For example employee1 has a
name, a salary, shift, age etc. and employee2 and other 101 employee have
all of it.
Call employee1.name or employee2.salary and assign it to a new variable,
something etc.
I can only repeat my previous advice. Instead of creating variables for
employee1, employee2, and so on make a list of employees:
$ cat employees.txt
Peter,3000
Paul,2000
Mary,1000
$ cat employees.py
#!/usr/bin/env python3
import csv
class Employee:
def __init__(self, name, salary):
self.name = name
self.salary = salary
if __name__ == __main__:
employees = []
with open(employees.txt) as f:
for row in csv.reader(f):
employees.append(Employee(row[0], int(row[1])))
for employee in employees:
print(employee.name, -- salary:, employee.salary, doubloons)
$ python3 employees.py
Peter -- salary: 3000 doubloons
Paul -- salary: 2000 doubloons
Mary -- salary: 1000 doubloons
You wouldn't want to reference Paul as employee2 -- what if the order in the
text file changed? Instead you can make a dict that maps name to employee...
employees_by_name = {}
for employee in employees:
name = employee.name
if name in employees_by_name:
raise ValueError(duplicate name {}.format(name))
employees_by_name[name] = employee
and use that dict to look up an employee:
while True:
name = input(enter a name )
if name == :
print(That's all folks)
break
if name not in employees_by_name:
print(unknown name)
else:
print(Salary:, employees_by_name[name].salary, doubloons)
$ python3 employees.py
Peter -- salary: 3000 doubloons
Paul -- salary: 2000 doubloons
Mary -- salary: 1000 doubloons
enter a name Peter
Salary: 3000 doubloons
enter a name Mary
Salary: 1000 doubloons
enter a name paul
unknown name
enter a name Paul
Salary: 2000 doubloons
enter a name
That's all folks
$
Thanks for your concern, I will try this. Actually, the main focus is that are
there any other Paul in my team. So i want to create a simple ID for employee
to distinguish two Paul. I belive that you have a solution for this.
--
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Re: generating unique variable name via loops
Fatih Güven wrote:
4 Kasım 2014 Salı 17:01:17 UTC+2 tarihinde Peter Otten yazdı:
Fatih Güven wrote:
4 Kasım 2014 Salı 15:37:59 UTC+2 tarihinde Peter Otten yazdı:
Veek M wrote:
Fatih Güven wrote:
4 Kas?m 2014 Sal? 13:29:34 UTC+2 tarihinde Fatih Güven yazd?:
I want to generate a unique variable name for list using python.
list1=...
list2=...
for x in range(1,10):
exec(list%d = [] % x)
Why would you do this?
I have a structured and repetitive data.
I was actually asking Veek M.
I want to read a .txt file line
by line and classified it to call easily. For example employee1 has a
name, a salary, shift, age etc. and employee2 and other 101 employee
have all of it.
Call employee1.name or employee2.salary and assign it to a new
variable, something etc.
I can only repeat my previous advice. Instead of creating variables for
employee1, employee2, and so on make a list of employees:
$ cat employees.txt
Peter,3000
Paul,2000
Mary,1000
$ cat employees.py
#!/usr/bin/env python3
import csv
class Employee:
def __init__(self, name, salary):
self.name = name
self.salary = salary
if __name__ == __main__:
employees = []
with open(employees.txt) as f:
for row in csv.reader(f):
employees.append(Employee(row[0], int(row[1])))
for employee in employees:
print(employee.name, -- salary:, employee.salary, doubloons)
$ python3 employees.py
Peter -- salary: 3000 doubloons
Paul -- salary: 2000 doubloons
Mary -- salary: 1000 doubloons
You wouldn't want to reference Paul as employee2 -- what if the order in
the text file changed? Instead you can make a dict that maps name to
employee...
employees_by_name = {}
for employee in employees:
name = employee.name
if name in employees_by_name:
raise ValueError(duplicate name {}.format(name))
employees_by_name[name] = employee
and use that dict to look up an employee:
while True:
name = input(enter a name )
if name == :
print(That's all folks)
break
if name not in employees_by_name:
print(unknown name)
else:
print(Salary:, employees_by_name[name].salary, doubloons)
$ python3 employees.py
Peter -- salary: 3000 doubloons
Paul -- salary: 2000 doubloons
Mary -- salary: 1000 doubloons
enter a name Peter
Salary: 3000 doubloons
enter a name Mary
Salary: 1000 doubloons
enter a name paul
unknown name
enter a name Paul
Salary: 2000 doubloons
enter a name
That's all folks
$
Thanks for your concern, I will try this. Actually, the main focus is that
are there any other Paul in my team. So i want to create a simple ID for
employee to distinguish two Paul. I belive that you have a solution for
this.
The easiest is to use the index:
#!/usr/bin/env python3
import csv
class Employee:
def __init__(self, name, salary):
self.name = name
self.salary = salary
if __name__ == __main__:
employees = []
with open(employees.txt) as f:
for row in csv.reader(f):
employees.append(Employee(row[0], int(row[1])))
for index, employee in enumerate(employees, 1):
print(#{}, name: {}.format(index, employee.name))
while True:
index = input(enter an index (1...{}) .format(len(employees)))
if index == :
print(That's all folks)
break
index = int(index) -1
employee = employees[index]
print(Name: {0.name}, Salary: {0.salary}.format(employee))
If the ID must stay the same for two runs of the script you have to put it
into the text file as another column. However, you are soon reaching
territory where a database is more convenient than a text file.
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Re: generating unique variable name via loops
On Tue, 04 Nov 2014 05:45:04 -0800, Fatih Güven wrote:
4 Kasım 2014 Salı 15:19:20 UTC+2 tarihinde Veek M yazdı:
Fatih Güven wrote:
4 Kas?m 2014 Sal? 13:29:34 UTC+2 tarihinde Fatih Güven yazd?:
I want to generate a unique variable name for list using python.
list1=...
list2=...
for x in range(1,10):
exec(list%d = [] % x)
This is okay but i can't use the method .append for example
list1.append(abc)
This is one solution using a dictionary of lists to maintain the name
association. It may not be the best method. It may not be the best
solution for you. It may not be the answer your instructor is looking
for, and it contains deliberate syntax errors.
lists = {}
for fn in filenames
infile = open(fn, r)
lists[fn] = []
for line in infile
lists[fn].append(line)
infile.close()
If you have to ask how to do this sort of thing, you probably shouldn't
be coding employee data processing systems anyway!
If this was a coding assignment for a course, you should have had
sufficient instruction in the relevant algorithms and language features
to be able to figure it out yourself.
In either case, what not explain what you tried, what you expected it to
do, and what it actually did.
--
Denis McMahon, denismfmcma...@gmail.com
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Re: generating unique variable name via loops
On Tue, 04 Nov 2014 05:53:04 -0800, Fatih Güven wrote: Call employee1.name or employee2.salary and assign it to a new variable, something etc. 1) Put the file into a database. 2) database calls -- Denis McMahon, denismfmcma...@gmail.com -- https://mail.python.org/mailman/listinfo/python-list
Re: generating unique variable name via loops
On 2014-11-04 05:53, Fatih Güven wrote: for x in range(1,10): exec(list%d = [] % x) Why would you do this? I have a structured and repetitive data. I want to read a .txt file line by line and classified it to call easily. For example employee1 has a name, a salary, shift, age etc. and employee2 and other 101 employee have all of it. Call employee1.name or employee2.salary and assign it to a new variable, something etc. -- This sounds remarkably like a CSV or tab-delimited file. If so, the way to do it would be import csv with open(data.txt, rb) as f: dr = csv.DictReader(f) for row in dr: do_something(row[Name], row[salary]) If the file format is more complex, it's often useful to create a generator to simplify the logic: class Person: def __init__(self, name=, salary=0, shift=, ): self.name = name self.salary = salary self.shift = shift def various_person_methods(self, ...): pass def people_from_file(f): build Person objects as you iterate over the file for row in file: person = Person( ... ) yield person with open(data.txt, r): for person in people_from_file(f): do_something(person) You can then reuse that generator with multiple files if you need. -tkc -- https://mail.python.org/mailman/listinfo/python-list
