Regex match all strings with the format {\...} in python

Question

I am unable to build a Regex that matches all possible strings of the format

{\some_text}

I tried to build myself a Regex but I was unable make it match ALL kinds of characters.

What I came up with: r"\{\\(.*)\}"

This did not work properly, it only matched {\~some_string}

This is what I am trying to achieve:

text = "F.N. Freitas, C. Singulani, G. Vila-Verde, Linea Science Server,: The Dark Energy Survey Data Release 2. Ap._J._Supp._Ser. 255, (2021).Alam S., A. de Mattia, A. Tamone, S. {\' A}vila, J.A. Peacock, V. Gonzalez-Perez, A. Smith, A. Raichoor, A.J. Ross, J.E. Bautista, E. Burtin, J. Comparat, K.S. Dawson, H. du Mas des Bourboux, S. Escoffier, H. Gil-Mar{\'\i}n, S. Habib, K. Heitmann, J. Hou, F.G. Mohammad, E.M. Mueller, R. Neveux, R. Paviot, W.J. Percival, G. Rossi, V. Ruhlmann-Kleider, R. Tojeiro, M. Vargas Maga{\~n}a, C. Zhao, G.B. Zhao: The completed SDSS-IV extended Baryon Oscillation Spectroscopic Survey: N-body mock challenge for the eBOSS emission line galaxy sample. Mon._Not._R._Astron._Soc. 504, (2021).Alam S., J.A. Peacock, D.J. Farrow, J. Loveday, A.M. Hopkins: Using GAMA to probe the impact of small-scale galaxy physics on nonlinear redshift-space distortions. Mon._Not._R._Astron._Soc. 503, (2021).Alam S., M. Aubert, S. Avila, C. Balland, J.E. Bautista, M.A. Bershady, D. Bizyaev, M.R. Blanton, A.S. Bolton, J. Bovy, J. Brinkmann, J.R. Brownstein, E. Burtin, S. Chabanier, M.J. Chapman, P.D. Choi, C.H. Chuang, J. Comparat, M.C. Cousinou, A. Cuceu, K.S. Dawson, S. de la Torre, A. de Mattia, V.S. Agathe, H.M. des Bourboux, S. Escoffier, T. Etourneau, J. Farr, A. Font-Ribera, P.M. Frinchaboy, S. Fromenteau, H. Gil-Mar{\'\i}n, J.M. Le Goff, A.X. Gonzalez-Morales, V. Gonzalez-Perez, K. Grabowski, J. Guy, A.J. Hawken, J. Hou, H. Kong, J. Parker, M. Klaene, J.P. Kneib, S. Lin, D. Long, B.W. Lyke, A. de la Macorra, P. Martini, K. Masters, F.G. Mohammad, J. Moon, E.M. Mueller, A. Mu{\~n}oz-Guti{\'e}rrez, A.D. Myers, S. Nadathur, R. Neveux, J.A. Newman, P. Noterdaeme, A. Oravetz, D. Oravetz, N. Palanque-Delabrouille, K. Pan, R. Paviot, W.J. Percival, I. P{\'e}rez-R{\`a}fols, P. Petitjean, M.M. Pieri, A. Prakash, A. Raichoor, C. Ravoux, M. Rezaie, J. Rich, A.J. Ross, G. Rossi, R. Ruggeri, V. Ruhlmann-Kleider, A.G. S{\'a}nchez, F.J. S{\'a}nchez, J.R. S{\'a}nchez-Gallego, C. Sayres, D.P. Schneider, H.J. Seo, A. Shafieloo, A. Slosar, A. Smith, J. Stermer, A. Tamone, J.L. Tinker, R. Tojeiro, M. Vargas-Maga{\~n}a, A. Variu, Y. Wang, B.A. Weaver, A.M. Weijmans, C. Y{\`e}che, P. Zarrouk, C. Zhao, G.B. Zhao, Z. Zheng: Completed SDSS-IV extended Baryon Oscillation Spectroscopic Survey: Cosmological implications from two decades of spectroscopic surveys at the Apache Point Observatory. Physical_Review_D 103, (2021).Alam S., N.P. Ross, S. Eftekharzadeh, J.A. Peacock, J. Comparat, A.D. Myers, A.J. Ross: Quasars at intermediate redshift are not special; but they are often satellites. Mon._Not._R._Astron._Soc. 504, (2021).Alonso-Herrero A., S. Garc{\'\i}a-Burillo, S.F. H{\"o}nig, I. Garc{\'\i}a-Bernete, C. Ramos Almeida, O. Gonz{\'a}lez-Mart {'hallo}"


encodings = {
    "'": u'\u0300',
    "'\\": u'\u0301',
    "^": u'\u0302',
    "~": u'\u0303',
    "o":  u'\u00D8',
    "ss": 'ß'

}

# remove the encoding and replace it with its corresponding character
def repl(m):
    string = m.group()
    get_open_bracket_idx = string.find('{')
    get_close_bracket_idx = string.find('}')
    encoding = substring.substringByChar(
        string, startChar=string[get_open_bracket_idx + 1], endChar=string[get_close_bracket_idx - 2])
    string_content = string[get_close_bracket_idx - 1]
    string_and_encoding = encoding + string
    string_content = encodings.get(encoding, string_content) + string_content
    print()
    print(f'encoding: {encoding}')
    print(f'string content: {string_content}')
    print()
    return string_content


# This nearly works, it just matches {'some_text} which it shouldnt
changed_text = re.sub(r'\{\\?[^{}]*}', repl, text)
print(changed_text)

Answer 1

You need a regex that will match {, then capture any non-word chars into Group 1 and then a letter(s) into Group 2 before closing }. Then, you will be able to check group contents and build replacement strings dynamically.

The regex will look like

\{([^\w\s]+|_)\s*(\w)}

See the regex demo. Details:

• \{ - a { char
• ([^\w\s]+|_) - Group 1: a special char
• \s* - zero or more whitespaces
• (\w) - Group 2: any word char
• } - } char.

Sample implementation in Python:

import re
text = r"{\' A}vila,  Y{\`e}che, {'hallo}"

encodings = {
    "\\'": u'\u0300',
    "\\`": u'\u0302',
}

def repl(m):
    encoding = m.group(1)
    string_content = m.group(2)
    if encoding in encodings:
        return string_content + encodings[encoding]
    return string_content

changed_text = re.sub(r'\{([^\w\s]+|_)\s*(\w)}', repl, text)
print(changed_text)
# => Àvila,  Yêche, {'hallo}