module containing miscelanous functions used in BKchem that don't
fit anywhere else. Does not contain any objects
        
            | Functions |  | 
        
        |  | 
            |  | difference | 
        
        | 
difference ( a,  b )
 returns difference of 2 lists ( a-b) | 
            |  | extend_bbox | 
        
        | 
extend_bbox ( bbox,  pixels=1 )
 | 
            |  | factorial | 
        
        | 
factorial ( x )
 | 
            |  | filter_unique | 
        
        | 
filter_unique ( items )
 | 
            |  | gen_combinations | 
        
        | 
gen_combinations ( items,  n )
 | 
            |  | gen_variations | 
        
        | 
gen_variations ( items,  n )
 | 
            |  | gen_variations_and_one | 
        
        | 
gen_variations_and_one ( items,  length )
 | 
            |  | has_one_value_only | 
        
        | 
has_one_value_only ( iterable )
 | 
            |  | intersection | 
        
        | 
intersection ( a,  b )
 returns intersection of 2 lists | 
            |  | lazy_apply | 
        
        | 
lazy_apply ( function,  arguments )
 similar to apply but returns a callable (lambda) that performs the apply when called. | 
            |  | len_and_ending | 
        
        | 
len_and_ending ( iterable )
 | 
            |  | list_difference | 
        
        | 
list_difference ( list )
 return a list of differences between list members,
  the list is by 1 shorter than the original | 
            |  | normalize_coords | 
        
        | 
normalize_coords ( coords )
 | 
            |  | plural_or_singular | 
        
        | 
plural_or_singular ( iterable )
 useful for string construction such as you have %d apple%s% (len(apples), plural_or_singular( apples) | 
            |  | reverse | 
        
        | 
reverse ( iterable )
 | 
            |  | reverse_molecule_formula | 
        
        | 
reverse_molecule_formula ( formula )
 | 
            |  | signum | 
        
        | 
signum ( a )
 | 
            |  | smallest_common_bbox | 
        
        | 
smallest_common_bbox ( bboxes )
 | 
            |  | split_number_and_unit | 
        
        | 
split_number_and_unit ( txt )
 | 
            |  | x_over_y | 
        
        | 
x_over_y ( x,  y )
 |