我正在尝试格式化字符串，以便两者之间的所有内容都对齐。
APPLES $.99 214
kiwi $1.09 755
我正在尝试这样做：
fmt = ('{0:30}{1:30}{2:30}'.format(Fruit,price,qty))
我将如何让一列排队？我阅读了文档，但我很困惑。我在想它{1:30}会变成 30 个空格，然后它会打印下一个项目，但它似乎距离上一个项目结束的地方有 30 个空格。
谢谢
str.format()使您的字段在可用空间内左对齐。使用对齐说明符更改对齐方式：
'<'强制字段在可用空间内左对齐（这是大多数对象的默认设置）。
'>'强制字段在可用空间内右对齐（这是数字的默认设置）。
'='强制将填充放在符号之后（如果有）但在数字之前。这用于以“+000000120”形式打印字段。此对齐选项仅对数字类型有效。
'^'强制场在可用空间内居中。
这是一个示例（左右对齐）：
>>> for args in (('apple', '$1.09', '80'), ('truffle', '$58.01', '2')):
... print '{0:<10} {1:>8} {2:>8}'.format(*args)
...
apple $1.09 80
truffle $58.01 2
使用 python3 f-strings（不是你的例子，而是我的例子）：
alist = ["psi", "phi", "omg", "chi1", "chi2", "chi3", "chi4", "chi5", "tau"]
for ar in alist:
print(f"{ar: >8}", end=" ")
print()
for ar in alist:
ang = ric.get_angle(ar)
print(f"{ang:8.4}", end=" ")
print()
生成
psi phi omg chi1 chi2 chi3 chi4 chi5 tau
4.574 -85.28 178.1 -62.86 -65.01 -177.0 80.83 8.611 115.3
我认为更好的方法是根据内容自动调整列宽
rows = [('apple', '$1.09', '80'), ('truffle', '$58.01', '2')]
lens = []
for col in zip(*rows):
lens.append(max([len(v) for v in col]))
format = " ".join(["{:<" + str(l) + "}" for l in lens])
for row in rows:
print(format.format(*row))
输出：
apple $1.09 80
truffle $58.01 2
直到现在我才知道 Python 有用于格式化列的解决方案 - 我决定研究它以防万一，因为我已经为另一种没有内置解决方案 ( Lua ) 的语言创建了自己的解决方案，并且由于 Logic 是通用的，因此我只需敲几下键就将其移植到 Python。
知道 Python 有自己的解决方案，我将考虑将其集成到我当前的解决方案中。
但是，当我创建了一个替代解决方案时，我将继续在此处发布我的解决方案，以便您了解我的解决方案的用户友好性 - 我对 Python 的抱怨之一是某些格式不那么直观，例如三元运算符False，True（老实说，True，False 与首先声明一起会更好），而其他人只是奇怪......
示例函数显示 Truncate 正在使用中（注意：一些逻辑成本不是必需的，仍在移动 - 例如 if _truncate ... 等）还显示了格式列系统...
这是非常基本的 - 将制表符转换为空格，计算列的长度，如果有太多则添加空格 - 如果文本过多，则将其切掉（我的其他解决方案有一个可以使用的缓冲区或边框，因此会显示边框字符，并强制列之间最少有 1 个空白字符 - 我还没有机会将它添加到 Python 变体中）等等......
它非常适合调试和输出..
有几个主要函数... String.FormatColumn( [ _width, _text ], ... ), String.FormatSimpleColumn( _width, [ _text, ... ] 和 String.FormatColumnEx( _empty_chars, [ _width, _text ], ... )..
String.FormatSimpleColumn 采用一次宽度，并将其用于所有列，仅重复文本..
String.FormatColumn 采用每列的宽度和文本...
String.FormatColumnEx 与 FormatColumn 相同，只是它允许您指定要使用的字符而不是空格 - 我通常使用小数或其他字符作为索引行...。
对于我的 Lua 实现，我还可以选择修剪正确的空格，但最终只是使用辅助函数来修剪不需要的空格......我留下它们是因为如果你设置了列，你可以简单地附加一些东西到函数调用之外的字符串，如果你想......修剪很简单......这也意味着你可以简单地链接函数调用以获得完全相同的结果，而不是链接参数......无论哪个看起来最适合你......
##
## Sandbox - All Works, if public, are released under the ACL or Acecool Company License - Josh 'Acecool' Moser
##
##
## Declarations for Globals, CONSTants, ENUMeration, etc..
##
## Define the tab width in terms of how many space-chars are used per tab character - Pi uses 8, Windows uses 4, some use 2, etc..
CONST_TAB_WIDTH = 4
##
## String Library - This library only includes Format Column debugging output format system..
##
class String:
##
##
##
def FormatColumnStripR( _width = 25, _text ='', *_varargs ):
return String.FormatColumn( _width, _text, *_varargs ).rstrip( )
##
##
##
def FormatSimpleColumnStripR( _width = 25, *_varargs ):
return String.FormatSimpleColumn( _width, *_varargs ).rstrip( )
##
## Helper function which lets you define width for each text, and it repeats it for you so you can repeat text and all columns will be the same width
##
## Purpose:
## The purpose of the Format Column Helpers is to improve data output, primarily for debugging so output is easier to follow..
## Usage:
## String.FormatColumn( 25, 'Text / Key', 15, 'Some Value', 15, 'Another Key', 50, 'Another Value' )
## String.FormatColumn( 25, 'Text / Key', 15, 'Some Value', 15, 'Another Key', 50, 'Another Value' )
## String.FormatColumn( 25, 'Key', 15, 'Some', 15, 'Another', 50, 'Value' )
##
## Output:
## Text / Key Some Value Another Key Another Value <LINE END>
## Text / Key Some Value Another Key Another Value <LINE END>
## Key Some Another Value <LINE END>
##
def FormatColumn( _width = 25, _text = '', *_varargs ):
return String.FormatColumnEx( ' ', _width, _text, *_varargs )
##
## Helper function which lets you define width for each text, and it repeats it for you so you can repeat text and all columns will be the same width
##
## Purpose:
## The purpose of the Format Column Helpers is to improve data output, primarily for debugging so output is easier to follow..
## Usage:
## String.FormatColumnEx( '.', 25, 'Text / Key', 15, 'Some Value', 15, 'Another Key', 50, 'Another Value' )
## String.FormatColumnEx( ' ', 25, 'Text / Key', 15, 'Some Value', 15, 'Another Key', 50, 'Another Value' )
## String.FormatColumnEx( ' ', 25, 'Key', 15, 'Some', 15, 'Another', 50, 'Value' )
##
## Output:
## Text / Key...............Some Value.....Another Key....Another Value.....................................<LINE END>
## Text / Key Some Value Another Key Another Value <LINE END>
## Key Some Another Value <LINE END>
##
def FormatColumnEx( _empty_char = ' ', _width = 25, _text = '', *_varargs ):
## Make sure our text is a string
_text = str( _text )
## For each tab used, calculate how many spaces should be used with minimum of 1 and maximum of 4 being the range depending which snap-point is used.. Then strip that tab and add spaces in its place..
_text = _text.expandtabs( CONST_TAB_WIDTH )
## Count how many additional arguments we have
_count = len( _varargs )
## Since our Ex function, this, must use a paired-system, we make sure the rounded division is > 0
_more = ( round( _count / 2, 0 ) > 0 )
## How many repeating chars do we need to create?
_reps = ( _width - len( _text ) )
## Build a string to fill the empty column space with spaces so everything lines up - as long as the right font is used ( where all chars are the same size )
_empty = _empty_char * _reps
## Now we ensure our text is limited to the _width size - data going over is truncated...TernaryFunc( _reps > 0, _empty, _empty )
## _data = String.SubStr( _text + ( _empty ), 0, _width )
## _data = ( _text + ( _empty ) )[ : _width ]
_data = String.Truncate( _text + ( _empty ), _width )
## If we have more cars
if ( _more ):
## Recursive call by shifting our VarArgs left so they populate _width and _text - then add the result to the data var... This only stops when no more paired options are left...
_data = _data + String.FormatColumnEx( _empty_char, *_varargs )
## Return the data..
return _data
##
## Helper function which lets you define width once, and it repeats it for you so you can repeat text and all columns will be the same width
##
## Purpose:
## The purpose of the Format Column Helpers is to improve data output, primarily for debugging so output is easier to follow..
## Usage:
## String.FormatSimpleColumn( 15, 'Text / Key', 'Some Value', 'Another Key', 'Another Value' )
## String.FormatSimpleColumn( 15, 'Key', 'Some', 'Another', 'Value' )
##
## Output:
## Text / Key Some Value Another Key Another Value <LINE END>
## Key Some Another Value <LINE END>
##
def FormatSimpleColumn( _width = 25, *_varargs ):
## Count how many text elements we have...
_count = len( _varargs )
## Set up our return var
_data = ''
## If we have at least 1 text element to set-up into a column
if ( _count > 0 ):
## Then we loop through each vararg
for _text in _varargs:
## If width is negative, use the length of the string plus the absolute value of width as a buffer...
if ( _width < 0 ):
_data = _data + String.FormatColumn( len( str( _text ) ) + abs( _width ), str( _text ) )
else:
## And we use a pseudo recursive call on the FormatColumnEx function - extra args...
_data = _data + String.FormatColumn( _width, str( _text ) )
## Return the data..
return _data
##
## SubString replacement
##
## Usage:
## _data = String.SubStr( _text, 0, 10 )
##
def SubStr( _text, _start, _end ):
return _text[ _start : _end ]
##
## Truncate characters of a string after _len'nth char, if necessary... If _len is less than 0, don't truncate anything... Note: If you attach a suffix, and you enable absolute max length then the suffix length is subtracted from max length... Note: If the suffix length is longer than the output then no suffix is used...
##
## Usage: Where _text = 'Testing', _width = 4
## _data = String.Truncate( _text, _width ) == Test
## _data = String.Truncate( _text, _width, '..', True ) == Te..
##
## Equivalent Alternates: Where _text = 'Testing', _width = 4
## _data = String.SubStr( _text, 0, _width ) == Test
## _data = _text[ : _width ] == Test
## _data = ( _text )[ : _width ] == Test
##
def Truncate( _text, _max_len = -1, _suffix = False, _absolute_max_len = True ):
## Length of the string we are considering for truncation
_len = len( _text )
## Whether or not we have to truncate
_truncate = ( False, True )[ _len > _max_len ]
## Note: If we don't need to truncate, there's no point in proceeding...
if ( not _truncate ):
return _text
## The suffix in string form
_suffix_str = ( '', str( _suffix ) )[ _truncate and _suffix != False ]
## The suffix length
_len_suffix = len( _suffix_str )
## Whether or not we add the suffix
_add_suffix = ( False, True )[ _truncate and _suffix != False and _max_len > _len_suffix ]
## Suffix Offset
_suffix_offset = _max_len - _len_suffix
_suffix_offset = ( _max_len, _suffix_offset )[ _add_suffix and _absolute_max_len != False and _suffix_offset > 0 ]
## The truncate point.... If not necessary, then length of string.. If necessary then the max length with or without subtracting the suffix length... Note: It may be easier ( less logic cost ) to simply add the suffix to the calculated point, then truncate - if point is negative then the suffix will be destroyed anyway.
## If we don't need to truncate, then the length is the length of the string.. If we do need to truncate, then the length depends on whether we add the suffix and offset the length of the suffix or not...
_len_truncate = ( _len, _max_len )[ _truncate ]
_len_truncate = ( _len_truncate, _max_len )[ _len_truncate <= _max_len ]
## If we add the suffix, add it... Suffix won't be added if the suffix is the same length as the text being output...
if ( _add_suffix ):
_text = _text[ 0 : _suffix_offset ] + _suffix_str + _text[ _suffix_offset: ]
## Return the text after truncating...
return _text[ : _len_truncate ]
##
##
##
def __example__( self ):
##
## Truncate Example...
##
_col_key = 20
_col_eq = 10
_col_res = 15
_row_eq = '=='
_text = 'Testing'
print( '--------------------------------------------- 8' )
_width = 8
print( String.FormatColumn( _col_key, 'Testing', _col_eq, _row_eq, _col_res, String.Truncate( _text, _width ) ) )
print( String.FormatColumn( _col_key, 'Testing', _col_eq, _row_eq, _col_res, String.Truncate( _text, _width, '..', True ) ) )
print( '--------------------------------------------- 7' )
_width = 7
print( String.FormatColumn( _col_key, 'Testing', _col_eq, _row_eq, _col_res, String.Truncate( _text, _width ) ) )
print( String.FormatColumn( _col_key, 'Testing', _col_eq, _row_eq, _col_res, String.Truncate( _text, _width, '..', True ) ) )
print( '--------------------------------------------- 6' )
_width = 6
print( String.FormatColumn( _col_key, 'Testin', _col_eq, _row_eq, _col_res, String.Truncate( _text, _width ) ) )
print( String.FormatColumn( _col_key, 'Test..', _col_eq, _row_eq, _col_res, String.Truncate( _text, _width, '..', True ) ) )
print( '--------------------------------------------- 5' )
_width = 5
print( String.FormatColumn( _col_key, 'Testi', _col_eq, _row_eq, _col_res, String.Truncate( _text, _width ) ) )
print( String.FormatColumn( _col_key, 'Tes..', _col_eq, _row_eq, _col_res, String.Truncate( _text, _width, '..', True ) ) )
print( '--------------------------------------------- 4' )
_width = 4
print( String.FormatColumn( _col_key, 'Test', _col_eq, _row_eq, _col_res, String.Truncate( _text, _width ) ) )
print( String.FormatColumn( _col_key, 'Te..', _col_eq, _row_eq, _col_res, String.Truncate( _text, _width, '..', True ) ) )
print( '--------------------------------------------- 3' )
_width = 3
print( String.FormatColumn( _col_key, 'Tes', _col_eq, _row_eq, _col_res, String.Truncate( _text, _width ) ) )
print( String.FormatColumn( _col_key, 'T..', _col_eq, _row_eq, _col_res, String.Truncate( _text, _width, '..', True ) ) )
print( '--------------------------------------------- 2' )
_width = 2
print( String.FormatColumn( _col_key, 'Te', _col_eq, _row_eq, _col_res, String.Truncate( _text, _width ) ) )
print( String.FormatColumn( _col_key, '..', _col_eq, _row_eq, _col_res, String.Truncate( _text, _width, '..', True ) ) )
print( '--------------------------------------------- 1' )
_width = 1
print( String.FormatColumn( _col_key, 'T', _col_eq, _row_eq, _col_res, String.Truncate( _text, _width ) ) )
print( String.FormatColumn( _col_key, '.', _col_eq, _row_eq, _col_res, String.Truncate( _text, _width, '..', True ) ) )
print( '--------------------------------------------- 0' )
_width = 0
print( String.FormatColumn( _col_key, '', _col_eq, _row_eq, _col_res, String.Truncate( _text, _width ) ) )
print( String.FormatColumn( _col_key, '', _col_eq, _row_eq, _col_res, String.Truncate( _text, _width, '..', True ) ) )
print( '---------------------------------------------' )