Aligning with string formatting

问题

I wish to achieve this sort of output with string formatting:

GBP......0.8639......0.8399

I have tried using the following code (i stands for currency and e[0] and e[1] are buy and sell values):

"{i:.<10}{e[0]:.^6}{e[1]:.>6}".format(i=i, e=e)

but the above code does not align the second number to the right, but it just adds it behind the first number, like this:

GBP.......0.86390.8399

How can I correct this?

回答1:

As a generalized solution:

• Use this format string if you want the right column, center and left column to be aligned right, center and left respectively:

  >>> '{0:.<10}{1:.^10}{2:.>10}'.format('GBP', 0.8639, 0.8399)
  'GBP.........0.8639......0.8399'
  
  # Another example
  >>> '{0:.<10}{1:.^10}{2:.>10}'.format('GBPTEST', 0.90, 0.8)
  'GBPTEST......0.9...........0.8'
  

• OR, this format string if you want all the columns except rightmost column to be aligned right:

  >>> '{0:.<10}{1:.>10}{2:.>10}'.format('GBP', 0.8639, 0.8399)
  'GBP...........0.8639....0.8399'
  
  # Another example
  >>> '{0:.<10}{1:.>10}{2:.>10}'.format('GBPTEST', 0.90, 0.8)
  'GBPTEST..........0.9.......0.8'
  

• OR, this format string if you want all the columns to be aligned left:

  >>> '{0:.<10}{1:.<10}{2:<10}'.format('GBP', 0.8639, 0.8399)
  'GBP.......0.8639....0.8399    '
  
  # Another example
  >>> '{0:.<10}{1:.<10}{2:<10}'.format('GBPTEST', 0.90, 0.8)
  'GBPTEST...0.9.......0.8       '
  

Change the value of 10 for each param based on the size of column you need.

---

Below will be the format string specific for the kind of params as mentioned in the question:

>>> '{i:.<10}{e[0]:.^10}{e[1]:.>10}'.format(i='GBP', e=(0.8639, 0.8399))
'GBP.........0.8639......0.8399'

# Another example
>>> '{i:.<10}{e[0]:.^10}{e[1]:.>10}'.format(i='GBPTEST', e=(0.90, 0.8))
'GBPTEST......0.9...........0.8'

回答2:

Increase the last number from 6 to 12.

"{i:.<10}{e[0]:.^6}{e[1]:.>12}".format(i=i, e=e)

This gives you

GBP.......0.8639......0.8399

回答3:

Your last two format specs only have a width of 6 and the values themselves are six digits, so there aren't any fill characters. If you want e[0] centered between i and e[1] with six dots on either side, construct the second format spec based on the length of e[0] - and don't specify a width for the other two.

>>> i = 'GPB'
>>> e = (0.8639, 0.8399)
>>> n = len(str(e[0]))
>>> s = '{i:}{e[0]:.^' + str(12+n) + '}{e[1]:}'
>>> s
'{i:}{e[0]:.^18}{e[1]:}'
>>> s.format(i = i, e = e)
'GPB......0.8639......0.8399'
>>> 

---

or

>>> i = 'GPB'
>>> e = (0.8639, 0.8399)
>>> s1 = '{{i:}}{{e[0]:.^{n:}}}{{e[1]:}}'
>>> n = len(str(e[0])) + 12
>>> s = s1.format(n=n)
>>> s
'{i:}{e[0]:.^18}{e[1]:}'
>>> s.format(i = i, e = e)
'GPB......0.8639......0.8399'
>>> 

来源：https://stackoverflow.com/questions/40978592/aligning-with-string-formatting