Python正则表达式——提取浮点模式

Question

I am trying to extract a particular "float" from a string, it contains multiple formatted "integers", "floats" and dates. The particular "float" in question is presided by some standardized text.

String sample

my_string = """03/14/2019 07:07 AM
💵Soles in mDm : 2864.35⬇
🔶BTC purchase in mdm: 11,202,782.0⬇
"""

I have been able to extract the desired float pattern for, 2864.35 , from my_string but if this particular float changes in pattern or another float with the same format shows up, my script won't return the desired result

regex = r"(\d+\.\d+)"
matches = re.findall(regex, my_string)
for match in matches:
    print(match)

• It might truncate the desired float because of inconsistent numerical formatting
• It might print two floats because the numerical pattern of an undesired float is too similar to be filtered out by current regular expression regex

Desired return from regular expression regex

• float with a flexible integer-part, sometimes comma is omitted ie. 45000.50 other times 45,000.50
• unique line identifier: Soles it could be upper/lower case
• line identifier: float prefix :
• it should only return one float

Some variances of desired float in the Second line of the string only

What you see bellow are three examples of the same line, the second line in my_string . The regex should be able to return only line number two despite any variations such as soles or Soles

• 💵Soles in mDm : 2864.35⬇
• soles MDM: 2,864.35
• Soles in mdm :2,864.355

Any assistance in editing or re-writing the current regular expression regex is greatly appreciated

Answer 1

EDIT - Hmmm... If it has to follow soles then hopefully this helps

Try these, granted my console can't take the extra characters, but based on your input:

>>> my_string = """03/14/2019 07:07 AM
Soles in mDm : 2864.35
BTC purchase in mdm: 11,202,782.0
Soles in mDm : 2864.35
soles MDM: 2,864.35
Soles in mdm :2,864.355
"""


>>> re.findall('(?i)soles[\S\s]*?([\d]+[\d,]*\.[\d]+)', my_string)

#Output
['2864.35', '2864.35', '2,864.35', '2,864.355']



>>> re.findall('[S|s]oles[\S\s]*?([\d]+[\d,]*\.[\d]+)', my_string)

#Output
['2864.35', '2864.35', '2,864.35', '2,864.355']

Answer 2

If you want to match multiple instances then just add the g flag other wise it'll only match the single instance. REGEX

(?<=:)\s?([\d,]*\.\d+)

With Python,

# coding=utf8
# the above tag defines encoding for this document and is for Python 2.x compatibility

import re

regex = r"(?<=:)\s?([\d,]*\.\d+)"

test_str = ("\n"
    "    💵Soles in mDm : 2864.35⬇\n"
    "    soles MDM: 2,864.35\n"
    "    Soles in mdm :2,864.355\n")

matches = re.search(regex, test_str, re.IGNORECASE)

if matches:
    print ("Match was found at {start}-{end}: {match}".format(start = matches.start(), end = matches.end(), match = matches.group()))

    for groupNum in range(0, len(matches.groups())):
        groupNum = groupNum + 1

        print ("Group {groupNum} found at {start}-{end}: {group}".format(groupNum = groupNum, start = matches.start(groupNum), end = matches.end(groupNum), group = matches.group(groupNum)))