Segregation is obviously not a good thing, but there are some movies so completely directed at one gender that those of the other would be wise to avoid them altogether. That’s the case with “How to Be Single,” a tale of women seeking love and self-realization in New York City in which most of the male characters are either douchebags or dishrags and one is asked to believe that an obnoxious character such as the one played by Rebel Wilson is generally irresistible to guys of all kinds. Even more of a “chick flick” than earlier entries by these screenwriters (“The Wedding Date,” “He’s Just Not That Into You,” “Valentine’s Day”) and based on a novel by Liz Tuccillo, who once wrote for “Sex and the City,” the picture is so female-centric that while it should prove popular for girls’ night out, it may not be the right choice for a date on February 14.

The central character in the mix is Alice (Dakota Johnson, playing mousy quite convincingly), who suggests a separation from her long-time college boyfriend Josh (Nicholas Braun) so that she can live a singles life for awhile and prove to herself that they’re right together. This seems a pretty silly idea—and proves to be so—but he reluctantly agrees, and she’s off from Connecticut to New York City, where she moves in with her older sister Meg (Leslie Mann), an OB/GYN who’s devoted to her job and her single life, until an encounter with a darling infant abruptly convinces her she wants one of her own. A search for a sperm donor ensues, and before long she’s pregnant.

Meanwhile Alice has fallen in Robin (Wilson), the irrepressible receptionist at the law firm where she lands a job. Though it’s hardly credible that any serious firm would keep a brash, raunchy loudmouth like Robin on staff, they do, and she assigns herself the task of introducing Alice to the single life, which means endless rounds of partying and one-night stands. They drop into a bar run by Tom (Anders Holm), a charming cad so committed to non-commitment that he’s arranged his apartment to send the women he invites there packing as quickly as possible on the morning after, and he and Alice will quickly link up—though only briefly.

In fact, both move on to others. Tom becomes increasingly taken with Lucy (Alison Brie), who lives in an apartment above the bar but spends most of her time downstairs, where the WiFi signal for her laptop is better: she’s endlessly focused on dating websites attempting to find the perfect man. Lucy is a truly odd character. We’re never informed whether she has a job; all we’re told is that she volunteers reading books to kids at a local store. It’s there that she has one of those crazed meltdown scenes that scripters love to write as much as actors yearn to play them. It happens after a fellow she’s met online turns out to be a crumb uninterested in a long-term relationship (much to her distress), and shocks the urchins clustered around her by lamenting her life until a clerk named George (Jason Mantzoukas) intervenes—and immediately falls for her.

That’s not the only Big Moment the writers have contrived. Mann gets one too, when she harangues Ken (Jake Lacy), a lovable younger fellow who’s immediately entranced with Meg, about how she’s determined to remain unattached. (Of course, that rejection won’t last.) So does Mantzoukas. That one comes near the close, at a birthday party for Alice where our heroine finds herself simultaneously pursued by two men: David (Damon Wayans, Jr.), a widower still uptight over his wife’s death whom Alice has met “cute” on a jaunt to see the Rockefeller Center Christmas tree but who can’t get past his grief, and Josh, who by now has become engaged to another woman but wants to hook up one last time to see if he’s made the right choice. (Both have actually seemed rather good guys up until this point, but end up no better than most.) As for George, he tears into Tom at the party when the latter has the temerity to come on to Lucy, now George’s fiancee, after the bartender has decided that he might believe in commitment after all.

Robin doesn’t get one of those long monologues, perhaps because Wilson doesn’t have the chops to pull off extended dialogue. Instead the character just lurches from one scene to another, appearing periodically to swing her ample body on a dance floor, deliver some marginally offensive zinger or take a supposedly hilarious pratfall. Wilson does attempt a moment of pathos at one point, but one wonders whether she’ll ever be able to sustain anything beyond the “wild and crazy” character she’s coasted along on thus far. If not, one doubts her popularity will last very long.

The rest of the cast play their mostly single-note characters adequately, though curiously it’s the men who come off best, with Lacy’s boyish amiability as winning as it was in the otherwise deplorable “Love the Coopers,” Wayans smoothly ingratiating and Holm and Braun doing variations on the unreliably charming dude. But Johnson is drab, Mann oddly shrill and Brie simply nondescript, partially a result of the fact that Lucy is so thinly-written. Unfortunately, the stench of “Dirty Grandpa” still hangs over Mantzoukas, so one should be gentle in dealing with his work here. The picture is competently made from a technical standpoint, but hardly outstanding in any particular.

“How to Be Single” aims to say something about women learning not only to survive but to flourish without falling into conventional relationship expectations. But in the process it embraces so many sitcom clichés—mixed with periodic girls-gone-wild shtick—that any deeper message it might want to convey is lost in the shuffle.