#!/usr/bin/python -itt import numpy as np import pprint import ctypes from ROOT import gSystem gSystem.Load('pyfits_h.so') from ROOT import * class FactFits( fits ): """ -Fact Fits File- A Python wrapper for the fits-class implemented in pyfits.h provides easy access to the fits file meta data. * dictionary of file metadata - self.meta * dict of table metadata - self.columns * variable table column access, thus possibly increased speed while looping """ def __init__(self, path): """ creates meta and columns dictionaries """ self.path = path try: fits.__init__(self,path) except IOError: print 'problem accessing data file: ', data_file_name raise # stop ! no data self.meta = self._make_meta_dict() self.columns = self._make_columns_dict() self.treat_meta_dict() # list of columns, which are already registered # see method register() self._registered_cols = [] # dict of column data, this is used, in order to be able to remove # the ctypes of self._table_cols = {} # I need to count the rows, since the normal loop mechanism seems not to work. self._current_row = 0 self.stacked_cols = {} def _make_meta_dict(self): # intermediate variables for file metadata dict generation keys=self.GetPy_KeyKeys() values=self.GetPy_KeyValues() comments=self.GetPy_KeyComments() types=self.GetPy_KeyTypes() if len(keys) != len(values): raise TypeError('len(keys)',len(keys),' != len(values)', len(values)) if len(keys) != len(types): raise TypeError('len(keys)',len(keys),' != len(types)', len(types)) if len(keys) != len(comments): raise TypeError('len(keys)',len(keys),' != len(comments)', len(comments)) meta_dict = {} for i in range(len(keys)): type = types[i] if type == 'I': value = int(values[i]) elif type == 'F': value = float(values[i]) elif type == 'B': if values[i] == 'T': value = True elif values[i] == 'F': value = False else: raise TypeError("meta-type is 'B', but meta-value is neither 'T' nor 'F'. meta-value:",values[i]) elif type == 'T': value = values[i] else: raise TypeError("unknown meta-type: known meta types are: I,F,B and T. meta-type:",type) meta_dict[keys[i]]=(value, comments[i]) return meta_dict def _make_columns_dict(self): # intermediate variables for file table-metadata dict generation keys=self.GetPy_ColumnKeys() #offsets=self.GetPy_ColumnOffsets() #not needed on python level... nums=self.GetPy_ColumnNums() sizes=self.GetPy_ColumnSizes() types=self.GetPy_ColumnTypes() units=self.GetPy_ColumnUnits() # zip the values values = zip(nums,sizes,types,units) # create the columns dictionary columns = dict(zip(keys ,values)) return columns def stack(self, on=True): self.next() for col in self._registered_cols: if isinstance( self.dict[col], type(np.array('')) ): self.stacked_cols[col] = self.dict[col] else: # elif isinstance(self.dict[col], ctypes._SimpleCData): self.stacked_cols[col] = np.array(self.dict[col]) # else: # raise TypeError("I don't know how to stack "+col+". It is of type: "+str(type(self.dict[col]))) def register(self, input_str): columns = self.columns if input_str.lower() == 'all': for col in columns: self._register(col) else: #check if colname is in columns: if input_str not in columns: error_msg = 'colname:'+ input_str +' is not a column in the binary table.\n' error_msg+= 'possible colnames are\n' for key in columns: error_msg += key+'\n' raise KeyError(error_msg) else: self._register(input_str) # 'private' method, do not use def _register( self, colname): columns = self.columns local = None number_of_elements = int(columns[colname][0]) size_of_elements_in_bytes = int(columns[colname][1]) ctypecode_of_elements = columns[colname][2] physical_unit_of_elements = columns[colname][3] # snippet from the C++ source code, or header file to be precise: #case 'L': gLog << "bool(8)"; break; #case 'B': gLog << "byte(8)"; break; #case 'I': gLog << "short(16)"; break; #case 'J': gLog << "int(32)"; break; #case 'K': gLog << "int(64)"; break; #case 'E': gLog << "float(32)"; break; #case 'D': gLog << "double(64)"; break; # the fields inside the columns can either contain single numbers, # or whole arrays of numbers as well. # we treat single elements differently... if number_of_elements == 1: # allocate some memory for a single number according to its type if ctypecode_of_elements == 'J': # J is for a 4byte int, i.e. an unsigned long local = ctypes.c_ulong() un_c_type = long elif ctypecode_of_elements == 'I': # I is for a 2byte int, i.e. an unsinged int local = ctypes.c_ushort() un_c_type = int elif ctypecode_of_elements == 'B': # B is for a byte local = ctypes.c_ubyte() un_c_type = int elif ctypecode_of_elements == 'D': local = ctypes.c_double() un_c_type = float elif ctypecode_of_elements == 'E': local = ctypes.c_float() un_c_type = float elif ctypecode_of_elements == 'A': local = ctypes.c_uchar() un_c_type = chr elif ctypecode_of_elements == 'K': local = ctypes.c_ulonglong() un_c_type = long else: raise TypeError('unknown ctypecode_of_elements:',ctypecode_of_elements) else: if ctypecode_of_elements == 'B': # B is for a byte nptype = np.int8 elif ctypecode_of_elements == 'A': # A is for a char .. but I don't know how to handle it nptype = np.int8 elif ctypecode_of_elements == 'I': # I is for a 2byte int nptype = np.int16 elif ctypecode_of_elements == 'J': # J is for a 4byte int nptype = np.int32 elif ctypecode_of_elements == 'K': # B is for a byte nptype = np.int64 elif ctypecode_of_elements == 'E': # B is for a byte nptype = np.float32 elif ctypecode_of_elements == 'D': # B is for a byte nptype = np.float64 else: raise TypeError('unknown ctypecode_of_elements:',ctypecode_of_elements) local = np.zeros( number_of_elements, nptype) # Set the Pointer Address self.SetPtrAddress(colname, local) self._table_cols[colname] = local if number_of_elements > 1: self.__dict__[colname] = local self.dict[colname] = local else: # remove any traces of ctypes: self.__dict__[colname] = local.value self.dict[colname] = local.value self._registered_cols.append(colname) def treat_meta_dict(self): """make 'interesting' meta information available like normal members. non interesting are: TFORM, TUNIT, and TTYPE since these are available via the columns dict. """ self.number_of_rows = self.meta['NAXIS2'][0] self.number_of_columns = self.meta['TFIELDS'][0] # there are some information in the meta dict, which are alsways there: # there are regarded as not interesting: uninteresting_meta = {} uninteresting_meta['arraylike'] = {} uninteresting = ['NAXIS', 'NAXIS1', 'NAXIS2', 'TFIELDS', 'XTENSION','EXTNAME','EXTREL', 'BITPIX', 'PCOUNT', 'GCOUNT', 'ORIGIN', 'PACKAGE', 'COMPILED', 'CREATOR', 'TELESCOP','TIMESYS','TIMEUNIT','VERSION'] for key in uninteresting: if key in self.meta: uninteresting_meta[key]=self.meta[key] del self.meta[key] # the table meta data contains # loop over keys: # * try to find array-like keys arraylike = {} singlelike = [] for key in self.meta: stripped = key.rstrip('1234567890') if stripped == key: singlelike.append(key) else: if stripped not in arraylike: arraylike[stripped] = 0 else: arraylike[stripped] += 1 newmeta = {} for key in singlelike: newmeta[key.lower()] = meta[key] for key in arraylike: uninteresting_meta['arraylike'][key.lower()] = [] for i in range(arraylike[key]+1): if key+str(i) in meta: uninteresting_meta['arraylike'][key.lower()].append(meta[key+str(i)]) self.ui_meta = uninteresting_meta # make newmeta self for key in newmeta: self.__dict__[key]=newmeta[key] dict = self.__dict__.copy() del dict['meta'] del dict['ui_meta'] self.dict = dict def __iter__(self): """ iterator """ return self def next(self): """ used by __iter__ """ # Here one might check, if looping makes any sense, and if not # one could stop looping or so... # like this: # # if len(self._registered_cols) == 0: # print 'warning: looping without any registered columns' if self._current_row < self.number_of_rows: if self.GetNextRow() == False: raise StopIteration for col in self._registered_cols: if isinstance(self._table_cols[col], ctypes._SimpleCData): self.__dict__[col] = self._table_cols[col].value self.dict[col] = self._table_cols[col].value for col in self.stacked_cols: if isinstance(self.dict[col], type(np.array(''))): self.stacked_cols[col] = np.vstack( (self.stacked_cols[col],self.dict[col]) ) else: # elif isinstance(self.dict[col], ctypes._SimpleCData): self.stacked_cols[col] = np.vstack( (self.stacked_cols[col],np.array(self.dict[col])) ) #else: #raise TypeError("I don't know how to stack "+col+". It is of type: "+str(type(self.dict[col]))) self._current_row += 1 else: raise StopIteration return self def show(self): pprint.pprint(self.dict) if __name__ == '__main__': import sys if len(sys.argv) == 1: print 'usage:', sys.argv[0], 'fits-file-name' file = FactFits(sys.argv[1]) print '-'*70 print "opened :", sys.argv[1], " as 'file'" print print '-'*70 print 'type file.show() to look at its contents' print "type file.register( columnname ) or file.register('all') in order to register columns" print print " due column-registration you declare, that you would like to retrieve the contents of one of the columns" print " after column-registration, the 'file' has new member variables, they are named like the columns" print " PLEASE NOTE: immediatly after registration, the members exist, but they are empty." print " the values are assigned only, when you call file.next() or when you loop over the 'file'" print print "in order to loop over it, just go like this:" print "for row in file:" print " print row.columnname_one, row.columnname_two" print print "" print '-'*70