Hướng dẫn python formatting output into columns - đầu ra định dạng python thành cột

Để có được những chiếc bàn fancier như

---------------------------------------------------
| First Name | Last Name        | Age | Position  |
---------------------------------------------------
| John       | Smith            | 24  | Software  |
|            |                  |     | Engineer  |
---------------------------------------------------
| Mary       | Brohowski        | 23  | Sales     |
|            |                  |     | Manager   |
---------------------------------------------------
| Aristidis  | Papageorgopoulos | 28  | Senior    |
|            |                  |     | Reseacher |
---------------------------------------------------

Bạn có thể sử dụng công thức Python này:

'''
From //code.activestate.com/recipes/267662-table-indentation/
PSF License
'''
import cStringIO,operator

def indent[rows, hasHeader=False, headerChar='-', delim=' | ', justify='left',
           separateRows=False, prefix='', postfix='', wrapfunc=lambda x:x]:
    """Indents a table by column.
       - rows: A sequence of sequences of items, one sequence per row.
       - hasHeader: True if the first row consists of the columns' names.
       - headerChar: Character to be used for the row separator line
         [if hasHeader==True or separateRows==True].
       - delim: The column delimiter.
       - justify: Determines how are data justified in their column. 
         Valid values are 'left','right' and 'center'.
       - separateRows: True if rows are to be separated by a line
         of 'headerChar's.
       - prefix: A string prepended to each printed row.
       - postfix: A string appended to each printed row.
       - wrapfunc: A function f[text] for wrapping text; each element in
         the table is first wrapped by this function."""
    # closure for breaking logical rows to physical, using wrapfunc
    def rowWrapper[row]:
        newRows = [wrapfunc[item].split['\n'] for item in row]
        return [[substr or '' for substr in item] for item in map[None,*newRows]]
    # break each logical row into one or more physical ones
    logicalRows = [rowWrapper[row] for row in rows]
    # columns of physical rows
    columns = map[None,*reduce[operator.add,logicalRows]]
    # get the maximum of each column by the string length of its items
    maxWidths = [max[[len[str[item]] for item in column]] for column in columns]
    rowSeparator = headerChar * [len[prefix] + len[postfix] + sum[maxWidths] + \
                                 len[delim]*[len[maxWidths]-1]]
    # select the appropriate justify method
    justify = {'center':str.center, 'right':str.rjust, 'left':str.ljust}[justify.lower[]]
    output=cStringIO.StringIO[]
    if separateRows: print >> output, rowSeparator
    for physicalRows in logicalRows:
        for row in physicalRows:
            print >> output, \
                prefix \
                + delim.join[[justify[str[item],width] for [item,width] in zip[row,maxWidths]]] \
                + postfix
        if separateRows or hasHeader: print >> output, rowSeparator; hasHeader=False
    return output.getvalue[]

# written by Mike Brown
# //aspn.activestate.com/ASPN/Cookbook/Python/Recipe/148061
def wrap_onspace[text, width]:
    """
    A word-wrap function that preserves existing line breaks
    and most spaces in the text. Expects that existing line
    breaks are posix newlines [\n].
    """
    return reduce[lambda line, word, width=width: '%s%s%s' %
                  [line,
                   ' \n'[[len[line[line.rfind['\n']+1:]]
                         + len[word.split['\n',1][0]
                              ] >= width]],
                   word],
                  text.split[' ']
                 ]

import re
def wrap_onspace_strict[text, width]:
    """Similar to wrap_onspace, but enforces the width constraint:
       words longer than width are split."""
    wordRegex = re.compile[r'\S{'+str[width]+r',}']
    return wrap_onspace[wordRegex.sub[lambda m: wrap_always[m.group[],width],text],width]

import math
def wrap_always[text, width]:
    """A simple word-wrap function that wraps text on exactly width characters.
       It doesn't split the text in words."""
    return '\n'.join[[ text[width*i:width*[i+1]] \
                       for i in xrange[int[math.ceil[1.*len[text]/width]]] ]]

if __name__ == '__main__':
    labels = ['First Name', 'Last Name', 'Age', 'Position']
    data = \
    '''John,Smith,24,Software Engineer
       Mary,Brohowski,23,Sales Manager
       Aristidis,Papageorgopoulos,28,Senior Reseacher'''
    rows = [row.strip[].split[',']  for row in data.splitlines[]]

    print 'Without wrapping function\n'
    print indent[[labels]+rows, hasHeader=True]
    # test indent with different wrapping functions
    width = 10
    for wrapper in [wrap_always,wrap_onspace,wrap_onspace_strict]:
        print 'Wrapping function: %s[x,width=%d]\n' % [wrapper.__name__,width]
        print indent[[labels]+rows, hasHeader=True, separateRows=True,
                     prefix='| ', postfix=' |',
                     wrapfunc=lambda x: wrapper[x,width]]

    # output:
    #
    #Without wrapping function
    #
    #First Name | Last Name        | Age | Position         
    #-------------------------------------------------------
    #John       | Smith            | 24  | Software Engineer
    #Mary       | Brohowski        | 23  | Sales Manager    
    #Aristidis  | Papageorgopoulos | 28  | Senior Reseacher 
    #
    #Wrapping function: wrap_always[x,width=10]
    #
    #----------------------------------------------
    #| First Name | Last Name  | Age | Position   |
    #----------------------------------------------
    #| John       | Smith      | 24  | Software E |
    #|            |            |     | ngineer    |
    #----------------------------------------------
    #| Mary       | Brohowski  | 23  | Sales Mana |
    #|            |            |     | ger        |
    #----------------------------------------------
    #| Aristidis  | Papageorgo | 28  | Senior Res |
    #|            | poulos     |     | eacher     |
    #----------------------------------------------
    #
    #Wrapping function: wrap_onspace[x,width=10]
    #
    #---------------------------------------------------
    #| First Name | Last Name        | Age | Position  |
    #---------------------------------------------------
    #| John       | Smith            | 24  | Software  |
    #|            |                  |     | Engineer  |
    #---------------------------------------------------
    #| Mary       | Brohowski        | 23  | Sales     |
    #|            |                  |     | Manager   |
    #---------------------------------------------------
    #| Aristidis  | Papageorgopoulos | 28  | Senior    |
    #|            |                  |     | Reseacher |
    #---------------------------------------------------
    #
    #Wrapping function: wrap_onspace_strict[x,width=10]
    #
    #---------------------------------------------
    #| First Name | Last Name  | Age | Position  |
    #---------------------------------------------
    #| John       | Smith      | 24  | Software  |
    #|            |            |     | Engineer  |
    #---------------------------------------------
    #| Mary       | Brohowski  | 23  | Sales     |
    #|            |            |     | Manager   |
    #---------------------------------------------
    #| Aristidis  | Papageorgo | 28  | Senior    |
    #|            | poulos     |     | Reseacher |
    #---------------------------------------------

Trang công thức Python chứa một vài cải tiến về nó.

Làm cách nào để in các cột văn bản trong Python?

%D %s trong python là gì?

Làm thế nào để bạn căn chỉnh đầu ra trong Python?