`StringIO` objects implement the file API, so you can get their size in exactly the same way as you can with a `file` object: seek to the end and see where it goes.

    from StringIO import StringIO
    import os
    s = StringIO()
    s.write(&quot;abc&quot;)
    pos = s.tell()
    s.seek(0, os.SEEK_END)
    print s.tell()
    s.seek(pos)

As Kimvais mentions, you can also use the `len`, but note that that&#39;s specific to StringIO objects.  In general, a major reason to use these objects in the first place is to use them with code that expects a file-like object.  When you&#39;re dealing with a generic file-like object, you generally want to do the above to get its length, since that works with *any* file-like object.


By checking the __len__ attribute and using the __getvalue()__ method

    Type &quot;help&quot;, &quot;copyright&quot;, &quot;credits&quot; or &quot;license&quot; for more information.
    &gt;&gt;&gt; import StringIO
    &gt;&gt;&gt; s = StringIO.StringIO()
    &gt;&gt;&gt; s.write(&quot;foobar&quot;)
    &gt;&gt;&gt; s.len
    6
    &gt;&gt;&gt; s.write(&quot; and spameggs&quot;)
    &gt;&gt;&gt; s.len
    19
    &gt;&gt;&gt; s.getvalue()
    &#39;foobar and spameggs&#39;



I&#39;m trying out Entity Framework 4&#39;s Code First (EF CodeFirst 0.8) and am running into a problem with a simple model that has a 1 &lt;--&gt; 0..1 relationship, between `Person` and `Profile`. Here&#39;s how they&#39;re defined:

    public class Person
    {
        public int PersonId { get; set; }

        public string FirstName { get; set; }
        public string LastName { get; set; }
        public DateTime? DOB { get; set; }

        public virtual Profile Profile { get; set; }
    }

    public class Profile
    {
        public int ProfileId { get; set; }
        public int PersonId { get; set; }
        public string DisplayName { get; set; }

        public virtual Person Person { get; set; }
    }

The DB context looks like this:

    public class BodyDB : DbContext
    {
        public DbSet&lt;Person&gt; People { get; set; }   
    }

I didn&#39;t define a `DbSet` for `Profile` because I consider `People` to be its aggregate root. When I try to add a new `Person` - even one without a `Profile` with this code:

    public Person Add(Person newPerson)
    {
        Person person = _bodyBookEntities.People.Add(newPerson);
        _bodyBookEntities.SaveChanges();
        return person;
    }

I get the following error:

&gt; Cannot insert explicit value for identity column in table &#39;People&#39; when IDENTITY_INSERT is set to OFF. 

The `newPerson` object has a `0` for the `PersonId` property when I call `People.Add()`. The database tables are `People` and `Profiles`. `PersonId` is the PK of `People` and is an auto-increment Identity. `ProfileId` is the PK of `Profiles` and is an auto-incement Identity. `PersonId` is a non-null int column of `Profiles`.

What am I doing wrong? I think I&#39;m adhering to all the EF Code First&#39;s convention over configuration rules.

EF Code First giving me error Cannot insert explicit value for identity column in table &#39;People&#39; when IDENTITY_INSERT is set to OFF.

I&#39;m using Toplink essentials (JPA) + GlassFish v3 + NetBean 6.9

I have one table with composite primary key:

    table (machine)
    ----------------
    |PK machineId  |
    |PK workId     |
    |              |
    |______________|

I created 2 entity classes one for entity itself and second is PK class.

    public class Machine {
       @EmbeddedId
       protected MachinePK machinePK;
    
       //getter setters of fields..
    }
    
    public class MachinePK {
        @Column(name = &quot;machineId&quot;)
        private String machineId;
    
        @Column(name = &quot;workId&quot;)
        private String workId;
    
    }

Now.. **how do I write SELECT clause with JPQL with WHERE???**

This fails.

    SELECT m FROM Machine m WHERE m.machineId = 10

http://www.mail-archive.com/users@openjpa.apache.org/msg03073.html

According to the web page, add &quot;val&quot;? No it fails too.

       SELECT m FROM Machine m WHERE m.machineId.val = 10

In both case, the error is:

        Exception Description: Error compiling the query 
    [SELECT m FROM Machine m WHERE m.machineId.val = 10], 
    line 1, column 30: unknown state or association field 
    [MachineId] of class [entity.Machine].

How to write JPQL SELECT with embedded id?

And get the bytes of that StringIO object?

In Python, how do I check the size of a StringIO object?

<p>And get the bytes of that StringIO object?</p>


I am looking for a definitive answer to MATLAB&#39;s parfor for Python (Scipy, Numpy).

Is there a solution similar to parfor? If not, what is the complication for creating one?

UPDATE: Here is a typical numerical computation code that I need speeding up

    import numpy as np

    N = 2000
    output = np.zeros([N,N])
    for i in range(N):
        for j in range(N):
            output[i,j] = HeavyComputationThatIsThreadSafe(i,j)

An example of a heavy computation function is:

    import scipy.optimize
    
    def HeavyComputationThatIsThreadSafe(i,j):
        n = i * j
        
        return scipy.optimize.anneal(lambda x: np.sum((x-np.arange(n)**2)), np.random.random((n,1)))[0][0,0]


Parfor for Python

I have a string of raw HTTP and I would like to represent the fields in an object. Is there any way to parse the individual headers from an HTTP string?

    &#39;GET /search?sourceid=chrome&amp;ie=UTF-8&amp;q=ergterst HTTP/1.1\r\nHost: www.google.com\r\nConnection: keep-alive\r\nAccept: application/xml,application/xhtml+xml,text/html;q=0.9,text/plain;q=0.8,image/png,*/*;q=0.5\r\nUser-Agent: Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10_6_6; en-US) AppleWebKit/534.13 (KHTML, like Gecko) Chrome/9.0.597.45 Safari/534.13\r\nAccept-Encoding: gzip,deflate,sdch\r\nAvail-Dictionary: GeNLY2f-\r\nAccept-Language: en-US,en;q=0.8\r\n
    [...]&#39;



Parse raw HTTP Headers

    import ftplib
    import urllib2
    import os
    import logging
    logger = logging.getLogger(&#39;ftpuploader&#39;)
    hdlr = logging.FileHandler(&#39;ftplog.log&#39;)
    formatter = logging.Formatter(&#39;%(asctime)s %(levelname)s %(message)s&#39;)
    hdlr.setFormatter(formatter)
    logger.addHandler(hdlr)
    logger.setLevel(logging.INFO)
    FTPADDR = &quot;some ftp address&quot;

    def upload_to_ftp(con, filepath):
        try:
            f = open(filepath,&#39;rb&#39;)                # file to send
            con.storbinary(&#39;STOR &#39;+ filepath, f)         # Send the file
            f.close()                                # Close file and FTP
            logger.info(&#39;File successfully uploaded to &#39;+ FTPADDR)
        except, e:
            logger.error(&#39;Failed to upload to ftp: &#39;+ str(e))

This doesn&#39;t seem to work, I get syntax error, what is the proper way of doing this for logging all kind of exceptions to a file


python exception message capturing

What I understand from reading the documentation is that Python has a separate namespace for functions, and if I want to use a global variable in that function, I need to use `global`.

I&#39;m using Python 2.7 and I tried this little test

    &gt;&gt;&gt; sub = [&#39;0&#39;, &#39;0&#39;, &#39;0&#39;, &#39;0&#39;]
    &gt;&gt;&gt; def getJoin():
    ...     return &#39;.&#39;.join(sub)
    ...
    &gt;&gt;&gt; getJoin()
    &#39;0.0.0.0&#39;

It seems things are working fine even without `global`. I was able to access global variable without any problem.

Am I missing anything? Also, following is from Python documentation:

&gt; Names listed in a global statement
&gt; must not be defined as formal
&gt; parameters or in a for loop control
&gt; target, class definition, function
&gt; definition, or import statement.

While formal parameters and class definition make sense to me, I&#39;m not able to understand the restriction on for loop control target and function definition.

Use of &quot;global&quot; keyword in Python

I have a date variable: ``2011-01-15`` and I would like to get a boolean back if said date is within 3 days from TODAY. Im not quite sure how to construct this in Python. Im only dealing with date, not datetime.

My working example is a &quot;grace period&quot;. A user logs into my site and if the grace period is within 3 days of today, additional scripts, etc. are omitted for that user.

I know you can do some fancy/complex things in Python&#39;s date module(s) but Im not sure where to look.

Content Type	Original Author	Original Content on Stackoverflow
Question	TIMEX	View Question on Stackoverflow
Solution 1 - Python	Glenn Maynard	View Answer on Stackoverflow
Solution 2 - Python	Kimvais	View Answer on Stackoverflow

In Python, how do I check the size of a StringIO object?

Python Problem Overview

Python Solutions

Solution 1 - Python

Solution 2 - Python

How to write JPQL SELECT with embedded id?

EF Code First giving me error Cannot insert explicit value for identity column in table 'People' when IDENTITY_INSERT is set to OFF.

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