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changes.mady.by.user Mikhail Dubrovin

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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)

...
 Code Block
    print 'string properties:'
    print 'punctuation    :  ', string.punctuation
    print 'digits         :  ', string.digits
    print 'octdigits      :  ', string.octdigits
    print 'hexdigits      :  ', string.hexdigits
    print 'ascii_letters  :  ', string.ascii_letters
    print 'ascii_lowercase:  ', string.ascii_lowercase
    print 'ascii_uppercase:  ', string.ascii_uppercase
    print 'lowercase      :  ', string.lowercase
    print 'uppercase      :  ', string.uppercase
    print 'letters        :  ', string.letters
    print 'printable      :  ', string.printable
    print 'whitespace     :  ', string.whitespace      
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
Class name
 Code Block
self.__class__.__name__
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')
 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'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'):
        self.f=open(fname,'r')

    def __del__(self) :
	    print 'destructor'
        try return strftime(fmt, localtime(time_sec))

def get_gm_time_str(time_sec, fmt='%Y-%m-%d %H:%M:%S %Z'):
    return        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) :
       ...
       
class Derived(Base) :
    def __init__(self) :
        Base.__init__(self)
        # OR
        super(Derived, self).__init__()   
 
 
 
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:
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'

 Code Block
    def processConfigPars(self):
        print 'processConfigPars'
        try :
            cp.confpars.guiconfigparameters.close()
self.f=open(fname,'r')

        except : # AttributeError: #NameError 
def __del__(self) :
	    print 'destructor'
       cp.confpars.guiconfigparameters = guiconfigpars.GUIConfigParameters()try :
            cpself.confpars.guiconfigparameters.move(self.pos().__add__(QtCore.QPoint(100,330))) # window offset
f.close()

    def __call__(self) :
	    print 'this is a default method of this #object orcalled useas self.parentWidget().pos() for combined widgetsobj()'
Polymorphism
Derived class initialization
 Code Block
class Base :
    def __init__(self) :
      # cp.guifilebrowser.move(self.parentWidget().pos().__add__(QtCore.QPoint(240,40)))
.
       
class Derived(Base) :
    def __init__(self) :
        Base.__init__(self)
        # OR
        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
 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() 
 Code Block
    def closeEvent(self, event):
    print    try: # try to delete self object in the cp.confpars
            del cp.confpars.guiconfigparameters _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) > except1 # AttributeError:else '0'
    print 50*'_', '\nTest %s:' % tname
   pass #t0_sec 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;}' +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   = 'QPushButton#but_path:disabled {color: white; background-color: pink;}' +
                  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  '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:
<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):
        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)))
    
 Code Block
class GUIImage ( QtGui.QLabel ) :
    def __init__ (self, parent=None, app=None) :

        QtGuicp.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.
...
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 setPixmapForImagecloseEvent(self, event):
        if self.r_pixmap == None :
            self.s_pixmap = None
try: # try to delete self object in the cp.confpars
            del  self.clear()cp.confpars.guiconfigparameters 
        elseexcept # AttributeError:
            pass # silently ignore

Change style of buttons depending on status
For particular QPushButton it works:
 Code Block
self.sbut_pixmappath = QtGui.QPushButton('File:')
self.rbut_pixmappath.scaled(self.size(), QtCore.Qt.KeepAspectRatio)setObjectName('but_path')
self.but_path.setStyleSheet('QPushButton#but_path:pressed  {color: black; background-color: green;}' +
            self.setPixmap(self.s_pixmap)
              self.setAlignment(QtCore.Qt.AlignTop | QtCore.Qt.AlignLeft)
      'QPushButton#but_path:disabled {color: white; background-color: pink;}' +
       self.setScailedMask()

Grab image from monitor
 Code Block
    def grabImage(self):
        fname = tempfile.NamedTemporaryFile(mode='r+b',suffix='.ppm')
      'QPushButton  if( 0 == os.system('import -trim -frame -border %s' % (fname.name))) :
       {color:  blue; background-color:  self.r_pixmap = QtGui.QPixmap(QtGui.QImage(fname.name)) 
            self.setPixmapForImage()
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: 
FormatDescriptionQt's support
BMPWindows BitmapRead/write
GIFGraphic Interchange Format (optional)Read
JPGJoint Photographic Experts GroupRead/write
JPEGJoint Photographic Experts GroupRead/write
PNGPortable Network GraphicsRead/write
PBMPortable BitmapRead
PGMPortable GraymapRead
PPMPortable PixmapRead/write
TIFFTagged Image File FormatRead/write
XBMX11 BitmapRead/write
XPMX11 PixmapRead/write
 
Grab entire monitor window
...
 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
...
Use np.select
 Code Block
V = np.array(...)
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) :
Vmin, Vmax, Nbins1 <--- scalar valuer
indarr  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

...