Parsing the pathname

Code Block

path        = '/reg/d/psdm/cxi/cxif5315/calib/pnccd/pnccd-123456.data'

root, ext = os.path.splitext(path) # i.e. path='root-part.tail-part'
        ('/reg/d/psdm/cxi/cxif5315/calib/pnccd/pnccd-123456', '.data') # or '' if something is missing
basename  = os.path.basename(path)
 #       pnccd-123456.data 
dirname   = os.path.dirname(path)
  # /reg/d/psdm/cxi/cxif5315/calib/pnccd
lexist     lexist    = os.path.lexists(path)
        # False
isfile    = os.path.isfile(path)
        # False
isdir     = os.path.isdir(path)
    #    False
head, tail= os.path.split(path)    # i.e. path='head-part/tail-part'('/reg/d/psdm/cxi/cxif5315/calib/pnccd', 'pnccd-123456.data') # or '' if something is missing
...

http://docs.python.org/library/os.path.html

...

Join list of strings

Code Block
s = ' '.join(sys.argv)

Join path and name

Code Block
path_name = os.path.join(path,fname)

...

Code Block
exp = 'xpptut13' if 'tut' is in exp : <do something>

String alignment

Code Block
msg = '%s' % (k.ljust(16))

Useful Useful string parsing options

http://docs.python.org/library/string.html

...

Code Block
my_string.replace("abcde","cde")

...

String formatting

Code Block
s = 'some text %s %s' % (msg.ljust(30), str(val).rjust(30)

List of comprehension

list_of_x2 = [x*x for x in list_of_x]

list_of_x_selected = [x for x,y in zip(list_of_x, list_of_y) if y>0]

map - built-in method

Code Block
def f(x,y) : return x if y>0 else -x list = map(f, arrX, arrY)

Constructor, destructor etc.

Class string properties

Code Block

    print 'string properties:'
    print 'punctuation    :  ', string.punctuation

Code Block

class PeakListFile :
    def __init__(self, fname) :
	    print 'constructor'
 digits       self.f=open(fname,'r')

  :  def __del__(self) :
	', string.digits
    print 'destructor'
octdigits      :  try :', string.octdigits
    print 'hexdigits      :  self.f.close()
', string.hexdigits
    defprint __call__(self) :
	'ascii_letters  :  ', string.ascii_letters
    print 'thisascii_lowercase: is a default method of this object called as obj()'

Polymorphism

Derived class initialization

Code Block

class Base :
    def __init__(self) :
       ...', string.ascii_lowercase
    print 'ascii_uppercase:  ', string.ascii_uppercase
    print 'lowercase      :  ', string.lowercase
    print 'uppercase  
class Derived(Base) :
    :  ', string.uppercase
    print 'letters    def __init__(self) :    :  ', string.letters
    print 'printable   Base.__init__(self)    :  ', string.printable
    print 'whitespace     #: OR
  ', string.whitespace     super(Derived, self)

Class name

Code Block
self.__class__.__initname__()

Python - useful references

Built-in functions

http://docs.python.org/library/functions.html

setattr - gives dynamic variables in python

http://docs.python.org/library/functions.html#setattr

PyQt4

PyQt4 class references

All classes
Selected:

Open/close/move other GUI window

Try to close window if its object exists, othervise - open:

Code Block

    def processConfigPars(self):
        print 'processConfigPars'
        try :
            cp.confpars.guiconfigparameters.close()
        except : # AttributeError: #NameError 
            cp.confpars.guiconfigparameters = guiconfigpars.GUIConfigParameters()
            cp.confpars.guiconfigparameters.move(self.pos().__add__(QtCore.QPoint(100,330))) # window offset
            # or use self.parentWidget().pos() for combined widgets:
            # cp.guifilebrowser.move(self.parentWidget().pos().__add__(QtCore.QPoint(240,40)))
            cp.confpars.guiconfigparameters.show()

Note

Sometime it looks like the window does not want to move in specified position...
In particular I have observed, that everything is going correct untill the w.show(). then, suddenly happens moveEvent(), which changes the self.pos(). In my case it happened because at construction of the combined window, its size was changed and it was moved in origin... Reservation of larger window size solved this problem.

Close window and delete object

Function name

Code Block
sys._getframe().f_code.co_name

Function parameters

Code Block
locals() # returns (dict) of method input parameters

Converting integer to bin(), oct(), hex() string

using built-in functions

Code Block
ival = 123456 str_bin = bin(ival) str_oct = oct(ival) str_hex = hex(ival)

Time stamp

Code Block

from time import localtime, gmtime, strftime, clock, time

time_sec = time() # epoch time

def get_current_local_time_stamp(fmt='%Y-%m-%d %H:%M:%S %Z'):
    return strftime(fmt, localtime())

def get_current_gm_time_stamp(fmt='%Y-%m-%d %H:%M:%S %Z'):
    return strftime(fmt, gmtime())

def get_local_time_str(time_sec, fmt='%Y-%m-%d %H:%M:%S %Z'):
    return strftime(fmt, localtime(time_sec))

def get_gm_time_str(time_sec, fmt='%Y-%m-%d %H:%M:%S %Z'):
    return strftime(fmt, gmtime(time_sec))

Set PYTHONPATH

In command-line:

Code Block
setenv PYTHONPATH /reg/neh/home1/dubrovin/LCLS/git-work/pyapps:${PYTHONPATH}

In cshell script:

Code Block
alias setpp 'setenv PYTHONPATH /reg/neh/home1/dubrovin/LCLS/git-work/pyapps:${PYTHONPATH}'

In code:

Code Block
import os os.environ['PYTHONPATH'] = '/reg/neh/home1/dubrovin/LCLS/git-work/pyapps:%s' % os.environ.get('PYTHONPATH', '')

Replace symbols in string

Code Block
text.replace("\|",":").replace("-",".") range.replace('9999','end') msg.replace('\n',' ')

List of comprehension

list_of_x2 = [x*x for x in list_of_x]

list_of_x_selected = [x for x,y in zip(list_of_x, list_of_y) if y>0]

map - built-in method

Code Block
def f(x,y) : return x if y>0 else -x list = map(f, arrX, arrY)

Constructor, destructor etc.

Code Block

class PeakListFile :
    def __init__(self, fname) :
	    print 'constructor'
        self.f=open(fname,'r')

    def __del__(self) :
	    print 'destructor'
        try :

Code Block

    def closeEvent(self, event):
        try: # try to delete self object in the cp.confpars
            del cp.confpars.guiconfigparameters 
        except # AttributeError:
            pass # silently ignore

Change style of buttons depending on status

For particular QPushButton it works:

self.f.close()

    def __call__(self) :
	    print 'this is a default method of this object called as obj()'

Polymorphism

Derived class initialization

Code Block

class Base :
    def __init__(self) :

Code Block

self.but_path = QtGui.QPushButton('File:')
self.but_path.setObjectName('but_path')
self.but_path.setStyleSheet('QPushButton#but_path:pressed  {color: black; background-color: green;}' +
                        ...
    'QPushButton#but_path:disabled {color: white; background-color: pink;}' + 
class Derived(Base) :
    def __init__(self) :
        Base.__init__(self)
        # OR
      'QPushButton                   {color:  blue; background-color: yellow;}')

For entire application it should be like:

Code Block
app = QtGui.QApplication.instance() app.setStyleSheet('QLabel{color: #fff;} QPushButton{background-color: #000; color: #fff}')

but does not work for me...

Make window visible on the top

Code Block
widg.raise_()

Scroll down text in

Assuming

Code Block
self.box_txt = QtGui.QTextEdit() self.box_txt.setText('some text') self.box_txt.append('a lot of additional text, exceeding the window size') self.box_txt.ensureCursorVisible()

Scroll bar can be used, but result is not seen imidiately:

Code Block
scrol_bar_v = self.box_txt.verticalScrollBar() # QScrollBar scrol_bar_v.setValue(scrol_bar_v.maximum())

Moving text cursor with repaint() works immidiately:

Code Block
self.box_txt.moveCursor(QtGui.QTextCursor.End) self.box_txt.repaint()

Set optimal table-widget size

Code Block
self.table = QtGui.QTableWidget(rows, cols, self) ... self.table.setFixedWidth(self.table.horizontalHeader().length() + 4) self.table.setFixedHeight(self.table.verticalHeader().length() + 29)

Show image in QLabel

Assumes:

Code Block

class GUIImage ( QtGui.QLabel ) :
    def __init__ (self, parent=None, app=None) :

        QtGui.QLabel.__init__(self, parent)

        self.setGeometry(200, 100, 100, 100)
        self.setWindowTitle('Image For Grabber')

        self.setFrame()
        ...

i.e. self is an instance of QLabel.

Set pixmap for image

Code Block

    def setPixmapForImage(self):
        if self.r_pixmap == None :
            self.s_pixmap = None
            self.clear()
        else :
            self.s_pixmap = self.r_pixmap.scaled(self.size(), QtCore.Qt.KeepAspectRatio)
            self.setPixmap(self.s_pixmap)
            self.setAlignment(QtCore.Qt.AlignTop | QtCore.Qt.AlignLeft)
            self.setScailedMask()

Grab image from monitor

super(Derived, self).__init__()

Create/save temporary file

Code Block
import tempfile tmp_file = tempfile.NamedTemporaryFile(mode='r+b',suffix='.tiff') tfile = tmp_file.name

Good example of main

Code Block

import sys

def test_all() :
    print _sep_, '\n%s' % sys._getframe().f_code.co_name
    test_ricker()
    test_morlet()

#------------------------------
if __name__ == "__main__" :
    from time import time
    tname = sys.argv[1] if len(sys.argv) > 1 else '0'
    print 50*'_', '\nTest %s:' % tname
    t0_sec = time()
    if   tname == '0': test_all() 
    elif tname == '1': test_ricker()
    elif tname == '2': test_morlet()
    else : print 'Not-recognized test name: %s' % tname
    msg = 'End of test %s, consumed time (sec) = %.6f' % (tname, time()-t0_sec)
    sys.exit(msg)

Virtualenv

Code Block
virtualenv dir-name source <directoryName>/bin/activate.csh # for tcsh # or source <directoryName>/bin/activate # for bash pip install <packageName> ... work deactivate

Python - useful references

Built-in functions

http://docs.python.org/library/functions.html

setattr, getattr - set/get dynamic variables in python

http://docs.python.org/library/functions.html#setattr

PyQt4

Know How

QGraphicsScene item priority is set by setZValue(v)
All re-implemented Event methods like {{mouseMoveEvent(self, e)}} etc. in items will get control only if QGraphicsView their default version will be called.

PyQt4 class references

All classes
Selected:

Open/close/move other GUI window

Try to close window if its object exists, othervise - open:

Code Block

    def processConfigPars(self):

Code Block

    def grabImage(self):
        fname = tempfile.NamedTemporaryFile(mode='r+b',suffix='.ppm')print 'processConfigPars'
        if( 0 == os.system('import -trim -frame -border %s' % (fname.name))) :try :
            cp.confpars.guiconfigparameters.close()
        except : # AttributeError: #NameError 
            self.r_pixmap = QtGui.QPixmap(QtGui.QImage(fname.name)) 
            self.setPixmapForImage()
cp.confpars.guiconfigparameters = guiconfigpars.GUIConfigParameters()
            cp.confpars.guiconfigparameters.move(self.pos().__add__(QtCore.QPoint(100,330))) # window offset
            # or use self.parentWidget().pos() for combined widgets:
            # cp.guifilebrowser.move(self.parentWidget().pos().__add__(QtCore.QPoint(240,40)))
            cp.confpars.guiconfigparameters.show()

Note

Sometime it looks like the window does not want to move in specified position...
In particular I have observed, that everything is going correct untill the w.show(). then, suddenly happens moveEvent(), which changes the self.pos(). In my case it happened because at construction of the combined window, its size was changed and it was moved in origin... Reservation of larger window size solved this problem.

Close window and delete object

Code Block
def closeEvent(self, event): try: # try to delete self object in the cp.confpars del cp.confpars.guiconfigparameters except # AttributeError: pass # silently ignore

Change style of buttons depending on status

For particular QPushButton it works:

Code Block

self.but_path = QtGui.QPushButton('File:')
self.but_path.setObjectName('but_path')
self.but_path.setStyleSheet('QPushButton#but_path:pressed  {color: black; background-color: green;}' +
                            'QPushButton#but_path:disabled {color: white; background-color: pink;}' +
                            'QPushButton                   {color:  blue; background-color: yellow;}')

For entire application it should be like:

Code Block
app = QtGui.QApplication.instance() app.setStyleSheet('QLabel{color: #fff;} QPushButton{background-color: #000; color: #fff}')

but does not work for me...

Make window visible on the top

Code Block
widg.raise_()

Scroll down text in

Assuming

Code Block
self.box_txt = QtGui.QTextEdit() self.box_txt.setText('some text') self.box_txt.append('a lot of additional text, exceeding the window size') self.box_txt.ensureCursorVisible()

Scroll bar can be used, but result is not seen imidiately:

Code Block
scrol_bar_v = self.box_txt.verticalScrollBar() # QScrollBar scrol_bar_v.setValue(scrol_bar_v.maximum())

Moving text cursor with repaint() works immidiately:

Code Block
self.box_txt.moveCursor(QtGui.QTextCursor.End) self.box_txt.repaint()

Set optimal table-widget size

Code Block
self.table = QtGui.QTableWidget(rows, cols, self) ... self.table.setFixedWidth(self.table.horizontalHeader().length() + 4) self.table.setFixedHeight(self.table.verticalHeader().length() + 29)

Show image in QLabel

Assumes:

Code Block

class GUIImage ( QtGui.QLabel ) :
    def __init__ (self, parent=None, app=None) :

        QtGui.QLabel.__init__(self, parent)

        self.setGeometry(200, 100, 100, 100)
        self.setWindowTitle('Image For Grabber')

        self.setFrame()
        ...

i.e. self is an instance of QLabel.

Set pixmap for image

Code Block

    def setPixmapForImage(self):
        if self.r_pixmap == None :
            self.s_pixmap = None
            self.clear()
        else :
            self.s_pixmap = self.r_pixmap.scaled(self.size(), QtCore.Qt.KeepAspectRatio)
            self.setPixmap(self.s_pixmap)
            self.setAlignment(QtCore.Qt.AlignTop | QtCore.Qt.AlignLeft)
            self.setScailedMask()

Grab image from monitor

Code Block

    import tempfile    
    def grabImage(self):
        fname = tempfile.NamedTemporaryFile(mode='r+b',suffix='.ppm')
        if( 0 == os.system('import -trim -frame -border %s' % (fname.name))) :
            self.r_pixmap = QtGui.QPixmap(QtGui.QImage(fname.name,'.ppm')) 
            self.setPixmapForImage()

Supported in QImage formats:

Format	Description	Qt's support
BMP	Windows Bitmap	Read/write
GIF	Graphic Interchange Format (optional)	Read
JPG	Joint Photographic Experts Group	Read/write
JPEG	Joint Photographic Experts Group	Read/write
PNG	Portable Network Graphics	Read/write
PBM	Portable Bitmap	Read
PGM	Portable Graymap	Read
PPM	Portable Pixmap	Read/write
TIFF	Tagged Image File Format	Read/write
XBM	X11 Bitmap	Read/write
XPM	X11 Pixmap	Read/write

Grab entire monitor window

...

When QPushButton is pressed and connected method is called, all button properties stay unchanged until the method. In order to see current changes one has to repaint widget. For example:method. In order to see current changes one has to repaint widget. For example:

Code Block
self.but_elog.setStyleSheet(cp.styleButton) self.but_elog.setEnabled(False) self.repaint()

Dialog boxes

For password

Code Block

    app = QtGui.QApplication(sys.argv)
    w = QtGui.QInputDialog()
    w.show()
    msg = 'To use %s and submitt messages in ELog\nauthentication for user %s is required\nPassword:' % (sys.argv[0], opts.usr)
    text, ok = w.getText(None, 'Authentication', msg, QtGui.QLineEdit.Password)
    w.close()
...

Code Block

            self.but_elog.setStyleSheet(cp.styleButton) 
            self.but_elog.setEnabled(False)
            self.repaint()

Graphics in PyQt4

Code Block

...
        self.poi1  = QtCore.QPoint(0,0)
        self.poi2  = QtCore.QPoint(0,0)
        self.rect1 = QtCore.QRect()
        self.rect2 = QtCore.QRect()

        self.pen1 = QtGui.QPen(QtCore.Qt.black) 
        self.pen2 = QtGui.QPen(QtCore.Qt.white) 
        self.pen1.setStyle(QtCore.Qt.DashLine) 
        self.pen2.setStyle(QtCore.Qt.DashLine) 
        self.pen1.setWidthF(1) 
        self.pen2.setWidthF(1)
...

     def paintEvent(self, e):
        super(GUIImage,self).paintEvent(e)
        qp = QtGui.QPainter()
        # or QPainter can be defined earlier and use it as   qp = self.qp
        qp.begin(self)
        #self.drawPixmap(qp)
        self.drawRect(qp)
        qp.end()
        self.update()

    def setPen(self, qp):
        self.pen.setStyle(QtCore.Qt.DashLine) 
        self.pen.setWidthF(1) 

    def drawRect(self, qp):
        if self.r_pixmap == None:
            return

        p1x, p1y = self.poi1.x(), self.poi1.y()
        p2x, p2y = self.poi2.x(), self.poi2.y()

        R=1
        if abs(p2x-p1x) < R : return
        if abs(p2y-p1y) < R : return

        self.rect1.setCoords( p1x,   p1y,   p2x,   p2y)
        self.rect2.setCoords( p1x+1, p1y+1, p2x-1, p2y-1)
        qp.setPen  (self.pen1)
        qp.drawRect(self.rect1);
        qp.setPen  (self.pen2)
        qp.drawRect(self.rect2);


    def drawPixmap(self, qp):
        if self.r_pixmap != None:
            qp.drawPixmap(0,0,self.s_pixmap)

...

Code Block
fig.clear()

Graphic

Code Block
import pyimgalgos.Graphics as gr axes.clear() axes.plot(xarr1, yarr1, '-r', xarr2, yarr2, '-g') gr.show(mode='do_not_hold')

Histogram

Code Block
axes.clear() axes.hist(arr, bins=100, range=(10,50), log=False) # log for vertical scale only

Image (with colorbar)

Code Block

img = axes.imshow(arr2d, interpolation='nearest', origin='bottom', aspect='auto')
img.set_clim(Amin,Amax)

cbar = self.fig.colorbar(img, orientation='vertical', \
                         fraction=0.1, pad=0.01, shrink=1.0, aspect=20)

        # fraction - of the 2d plot occupied by the color bar
        # pad      - is a space between 2d image and color bar
        # shrink   - factor for the length of the color bar
        # aspect   - ratio length/width of the color bar

...

Other supported formats: gif, pdf, png, jpeg, eps

eps

Check tiff file

To check tiff file format one may use command:

% identify -verbose <file-name>.tiff

Save image in 16-bit TIFF file

...

Code Block

V = np.array(...)
Vmin, Vmax, Nbins1 <--- scalar valuer
indarr
Vmin, Vmax, Nbins1 <--- scalar valuer
indarr = np.int32( factor * (V-Vmin) )
arr = np.select([V==Vmax, indarr<0, indarr>Nbins1], [Nbins1, 0, 0], default=indarr)

protected division:

Code Block

def divideZeroProteced(nda_num, nda_den, val_subst_zero=0) :
    pro_num = np.int32( factor * (V-Vmin) )
arrselect([nda_den==0], [val_subst_zero], default=nda_num)
    pro_den = np.select([Vnda_den==Vmax0], indarr<0, indarr>Nbins1], [Nbins1, 0, 0], default=indarr)[1],              default=nda_den)
    return pro_num / pro_den

SciPy

Import

Code Block
#!/usr/bin/env python import numpy as np from scipy.optimize import curve_fit

...

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Page History

Versions Compared

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Key

Parsing the pathname

Join list of strings

Join path and name

String alignment

Useful Useful string parsing options

String formatting

List of comprehension

map - built-in method

Constructor, destructor etc.

Class string properties

Polymorphism

Derived class initialization

Class name

Python - useful references

Built-in functions

setattr - gives dynamic variables in python

PyQt4

PyQt4 class references

Open/close/move other GUI window

Close window and delete object

Function name

Function parameters

Converting integer to bin(), oct(), hex() string

Time stamp

Set PYTHONPATH

Replace symbols in string

List of comprehension

map - built-in method

Constructor, destructor etc.

Change style of buttons depending on status

Polymorphism

Derived class initialization

Make window visible on the top

Scroll down text in

Set optimal table-widget size

Show image in QLabel

Set pixmap for image

Grab image from monitor

Create/save temporary file

Good example of __main__

Virtualenv

Python - useful references

Built-in functions

setattr, getattr - set/get dynamic variables in python

PyQt4

Know How

PyQt4 class references

Open/close/move other GUI window

Close window and delete object

Change style of buttons depending on status

Make window visible on the top

Scroll down text in

Set optimal table-widget size

Show image in QLabel

Set pixmap for image

Grab image from monitor

Grab entire monitor window

Dialog boxes

For password

Graphics in PyQt4

Graphic

Histogram

Image (with colorbar)

Check tiff file

Save image in 16-bit TIFF file

SciPy

Import

Good example of main